Field of Invention The present invention provides ketolide derivatives, which can be used as antibacterial agents. Compounds described herein can be used for treating or preventing conditions caused by or contributed to by Gram-positive, Gram-negative or anaerobic bacteria, more particularly against, for example, Staphylococci, Streptococci, Enterococci, Haemophilus, Moraxalla spp., Chlamydia spp., Mycoplasm, Legionella spp., Mycobacteriwn, Helicobacter, Clostridium, Bacteroides, Corymbacterium, Bacillus, Enterobactericeae or any combination thereof. Also provided are processes for preparating compounds described herein, pharmaceutical compositions containing compounds described herein, and methods of treating bacterial infections. Background of the Invention First generation macrolides erythromycin A and early derivatives are characterized by bacteriostatic or bactericidal activity for most Gram-positive bacteria, atypical pathogens, and many community-acquired respiratory infections and in patients with penicillin allergy. However, erythromycin A causes numerous drug-drug interactions, has relatively poor absorption, poor local tolerance, loses its antibacterial activity under acidic conditions by degradation and the degraded products are known to be responsible for undesired side effects (Itoh, Z et al., Am. J. Physiol, 1984, 247:688; Omura, S et al, J. Med. Chem., 1987, 30:1943). Various erythromycin A derivatives have been prepared to overcome the acid instability and other problems associated with it. Roxithromycin, clarithromycin and azithromycin were developed to address the limitation of erythromycin A. Both clarithromycin and azithromycin were found to be important drugs in the treatment and prophylaxis of atypical mycobacterial infections in patients with HIV. Macrolides were found to be effective drugs in the treatment of many respiratory tract infections. However, increasing resistance among S. pneumoniae has prompted the search for new compounds that retain favorable safety profiles, retain a spectrum of activity and are confined to respiratory pathogens. Consequently, numerous investigators have prepared chemical derivatives of erythromycin A in an attempt to obtain analogs having modified or improved profiles of antibioticactivity. Ketolides exhibit greater efficacy and safety, have broader spectrum of activities, and are particularly effective against resistant pathogens; hence, ketolides have been developed as next generation macrolides. U.S. Patent No. 5,635,485 discloses erythromycin compounds that are reportedly useful in the treatment of bacterial infections in warm-blooded animals. -2- U.S. Patent No. 5,866,549 discloses semi-synthetic macrolides reportedly having antibacterial activity, as well as 6-O-substituted erythromycin ketolide derivatives and a method of treating bacterial infections. U.S. Patent Nos. 6,458,771 and 6,399,582 and PCX Publication Nos. WO 00/62783 and WO 00/44761 disclose ketolide antibacterials that are reportedly useful in treating bacterial and protozoal infections and in treating other conditions involving gastric motility. U.S. Patent No. 5,747,467 discloses erythromycin and antibacterial composition and a method of treating bacterial infection in warm-blooded animals. U.S. Patent No. 6,433,151 discloses erythromycin derivatives and their use as medicament for treating infections caused by particular Gram-positive bacteria, namely Haemophilus influenzae, and Morraxalla spp. U.S. Patent No. 6,472,372 discloses 6-O-carbamoyl ketolide antibacterials and methods of treating bacterial infections. U.S. Patent Application Nos. 2002/0115621 and 2003/0013665 disclose macrolide compounds that are said to be useful as antibacterial and antiprotozoal agents in mammals, including man, as well in fish and birds. Other ketolide compounds have also been reported, A. Denis and A. Bonnefoy, Drugs of the Future, 26(10):975-84 (2001), Champney W. S., etal, Current Microbiology, 42 :203-10 (2001). However, there remains a need for novel ketolide derivatives, which can be used as antibacterial agents on a wide variety of Gram-positive, Gram-negative or anaerobic bacteria. Summary of the Invention The present invention provides ketolide derivatives, which can be used in the treatment or prevention of bacterial infection, and processes for the synthesis of these compounds. Pharmaceutically acceptable salts, pharmaceutically acceptable solvates, enantiomers, diastereomers, polymorphs of these compounds having same type of activity are also provided. Pharmaceutical compositions containing the described compounds together with pharmaceutically acceptable carriers, excipients or diluents, which can be used for the treatment of bacterial infection.Thus in one aspect, provided herein are compounds having the structure of Formula I, pharmaceutically acceptable salts, pharmaceutically acceptable solvates, enantiomers, diastereomers or polymorphs thereof, wherein R1 can be hydrogen or a hydroxyl protecting group; R2 and R3 can independently be alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocycle, aralkyl, (heterocycle)alkyl or COR11, wherein R11 can be hydrogen, alkyl or aralkyl, with the proviso that R2 and R3 are not simultaneously methyl; W can be alkenyl, -G(CH2)qJ-, -CR9R10, -NR9- or -SO2, wherein q can be an integer of from 2 to 6; G can be no atom, -CO, -CS or -SO2; R9 and R10 can independently be hydrogen or alkyl; and J can be no atom, -CR9R10 or N(R12)(CH2)m, wherein m can be an integer of from 0 to 6; R9 and R10 can be the same as defined earlier; and R12 can be hydrogen, alkyl, alkylene, alkynyl, COR8 or -(CH2)m-R8, wherein R8 can be alkyl, aryl or heterocycle; R can be aryl or heterocycle; R4 can be alkyl, alkenyl or alkynyl; R' can be alkyl or -(CH2)r-U, wherein r can be an integer of from 1 to 4 and U can be alkenyl or alkynyl; and Y can be halogen, cyano or alkyl; Z can be oxygen, sulfur or NOR11, wherein R11 can be the same as defined earlier. These compounds can include one or more of the following embodiments. For example, R "7 "? can be heterocycle; R can be methyl; R can be alkyl (except methyl), alkenyl, cycloalkyl or COR11; W can be -G(CH2)qJ- or CR9R10, wherein G, q, J, R9, R10 and R11 can be the same as defined above. In another embodiment, R1 can be hydrogen or a hydroxy protecting group (wherein the <* o hydroxy protecting can be benzoyl, tetrahydropyranyl or a trialkylsilylether); R can be Cfy; R can be C2H5, -CH2-CH=CH2 or -CH2CH2F; W can be -(CH2)4-J-, wherein J can be CH2 or (CH2)0-i- wherein Xi-Xs can independently be CH or N; X4-Xg can independently be CH, CR4 or N; X9 can be O, S, N, NH or CH; X10 can be NH or S; Ra can be thienyl, furyl, pyrazolyl, oxazolyl, tetrazolyl, imidazolyl, pyridinyl, fluoropyridinyl, chloropyridinyl, aminopyridinyl, pyrazinyl, pyrimidinyl, aminopyrimidinyl, quinolinyl, pyrrolo-pyridyl, pyrrolo-thiazolyl or optionally substituted phenyl; R'a can be hydrogen or furyl; Rb can be hydrogen or amino; RC can be hydrogen, thienyl, furyl, pyrazolyl, pyrazinyl, pyridinyl, aminopyridinyl, pyrimidinyl, pyrrolyl, imidazolyl or optionally substituted phenyl; and Rd can be thienyl, pyrazolyl, imidazolyl, triazolyl, pyrrolyl or tetrahydrofuryl. In another aspect, provided herein are compounds selected from: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((3-imidazol-l-yl)-propyl)-imino] erythromycin A (Compound No. 1), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-niethyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((lH)-imidazo(4,5-b)-pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 2), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3H)-imidazo(4,5-b)-pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 3), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (CompoundNo. 4), 2-a-Fluoro-5-O-(31-N-desmethyl-3!-N-ethyl)-ll,12-dideoxy-3-0-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 5), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-cyclopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((3-imidazol-l-yl)-propyl)-imino] erythromycin A (Compound No. 6), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,ll-[oxycarbonyl-((3-imidazol-l-yl)-propyl)-imino] erythromycin A (Compound No. 7), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-n-propyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,ll-[oxycarbonyl-((3-imidazol-l-yl)-propyl)-imino] erythromycin A (Compound No. 8), -5- 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-n-propyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (CompoundNo. 9), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-cyclopropyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-(pyrrolo-(2,3-b)pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 10), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-(pyrrolo-(2,3-b)pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 11), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 12), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-l 2, ll-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 13), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-n-propyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-(imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 14), 2-a-Fluoro-5-O-(3'-N-desmethyl-3 '-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyrrolo-(2,3-b)-pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 15), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-((lH)-imidazo(4,5-b)-pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 16), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(purin-9-yl)-butyl)-imino)] erythromycin A (Compound No. 17), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-cyclopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-((3H)-imidazo(4,5-b)-pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 18), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(4-pyridin-3-yl-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 19), 2a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-methyl-N'-quinolin-4-ylmethyl)-2-aminoethyl)-iniino] erythromycin A (Compound No. 20),2-a-Fluoro-5-O-(3l-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-methyl-N'-pyridine-3-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 21), 2-a-Fluoro-5-O-(3'-N-desmethyl-3 '-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-methyl-N-pyridine-4-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 22), 2-a-Fluoro-5-O-(3l-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-methyl-N'-pyridine-2-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 23), -6- 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-foxycarbonyl^CN'-methyl-N'-pyridine^-ylmethyO-i-aminoethy^-imino] erythromycin A (Compound No. 24), 2-a-Fluoro-5-0-(3l-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-toxycarbonyl^CN'-methyl-N'-pyridine-S-ylmethyO^-aminoethyO-imino] erythromycin A (Compound No. 25), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-methyl-N'-pyridine-4-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 26), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-methyl-N'-quinoline-4-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 27), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-pyridine-3-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 28), 2-a-Fluoro-5-0- (3'-N-desmethyl-3'-N-allyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-acetyl-N'-pyridine-3-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 29), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-pyridine-3-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 30), 2-a-Fluoro-5-0- (3'-N-desmethyl-3'-N-ethyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N'-acetyl-Nl-pyridine-3-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 31), 2-cc-Fluoro-5-O- (3'-N-desmethyl-3'-N-ethyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N',N'-di-pyridine-3-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 32), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((N',N'-di-pyridine-3-ylmethyl)-2-aminoethyl)-imino] erythromycin A (Compound No. 33), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-0-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-(quinolin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 34), 2-a-Fluoro-5-O- (3'-N-desmethyl-3'-N-ethyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(quinolin-8-yl)-butyl)-imino)] erythromycin A (Compound No. 35), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-(pyridin-2-yl)-butyl)-imino)] erythromycin A (Compound No. 36), 2-a-Fluoro-5-O- (3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 37), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyridin-4-yl)-butyl)-imino)] erythromycin A (Compound No. 38), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyridin-2-yl)-butyl)-imino)] erythromycin A (Compound No. 39), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(pyridin-4-yl)-butyl)-imino)] erythromycin A (Compound No. 40), -7- 2-a-Fluoro-5-O- (3'-N-desmethyl-3'-N-allyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyridin-3-yl)-pentyl)-imino] erythromycin A (CompoundNo. 41), 2-a-Fluoro-5-O- (3'-N-desmethyl-3'-N-allyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-(pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 42), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 43), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 44), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-((5-nitro)-indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 45), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((lH)-imidazo[4,5-c]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 46), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(benzotriazol-2-yl)-butyl)-imino)] erythromycin A (Compound No. 47), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3H)-imidazo[4,5-c]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 48), 2-a-Fluoro-5-O-(3'-N-desmethyl-3 '-N-cyclopropyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-((4-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 49), 2-a-Fluoro-5-0-(3'-N-desmethyl-3 '-N-cyclopropyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-(benzotriazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 50), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-cyclopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-Omethy1-3-oxo-12,1 l-[oxycarbonyl-((4-(benzotriazol-2-yl)-butyl)-imino)] erythromycin A (Compound No, 51), 2-a-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-cyclopropyl)-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-((lH)-imdazo[4,5-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 52), 2-a-Fluoro-5 -O-(3 '-N-desmethyl-3 '-N-cyclopropyl)-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-(indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 53), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(benzotriazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 54), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 55), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3H)-imidazo[4,5-b]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 56), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-0-methyl-3- oxo-12,ll-[oxycarbonyl-((4-((4-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 57), -8- 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-(benzotriazol-2-yl)-butyl)-imino)] erythromycin A (Compound No. 58), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-(indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 59), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-0-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-((3H)-imidazo[4,5-b]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 60),2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-((5-nitro)-indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 61), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-((5-nitro)-indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 62), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-((5-fluoro)-indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 63), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(benzotriazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 64), 2-a-Fluoro-5-O-(3l-N-desmethyl-31-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-methyl)-benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 65), 2-a-Fluoro-5-O-(3l-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-niethyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-ethyl)-benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 66), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-isopropyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,1 l-[oxycarbonyl-((4-(benzotriazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 67), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-ethyl)-benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 68), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyridin-3-yl-imidazol)-l-yl)-butyl)-imino)] erythromycin A (Compound No. 69), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-methyl)-benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 70), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,1 l-[oxycarbonyl-((4-(pyrrolo[2,3-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 71), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((lH)-imidazo[4,5-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 72), -9- 2-a-Fluoro-5-0-(3'-N-desmethyl-3l-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-0-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-((3H)-imidazo[4,5-b]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 73), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-l 2, ll-[oxycarbonyl-((4-((5-nitro)-indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 74), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-((2-pyridin-3-ylmethyl)-benzoimidazol-1 -yl)-butyl)-imino)] erythromycin A (Compound No. 75), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-((2-pyridin-3-ylmethyl)-benzoimidazol-1 -yl)-butyl)-imino)] erythromycin A (Compound No. 76), 2-a-Fluoro-5-0-(3'-N-desmethyl-3l-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 77), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-((5-fluoro)-indol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 78), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((5,6-dimethyl)-benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 79), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-niethyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((5,6-dimethyl)-benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 80),2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3H)-imidazo[4,5-c]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 81), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-methyl)- (3H)-imidazo[4,5-b]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 82), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-((2-methyl)-(3H)-imidazo[4,5-b]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 83), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((lH)-imidazo[4,5-c]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 84), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((9-(4-amino-butyl)-9H-purin-6-yl)-imino] erythromycin A (Compound No. 85), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 86), 2-a-Fluoro-5-O-(3l-N-desmethyl-3'-N-acetyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 87), -10- 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-cyclopropyl methyl)-! 1,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-((3H)-imidazo[4,5-b]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 88), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl methyl)-! l,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,l l-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 89), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl methyl)-! l,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,l l-[oxycarbonyl-((4-(pyrrolo[2,3-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 90), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,l l-[oxycarbonyl-((4-(pyrrolo[2,3-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 91), 2-a-Fluoro-5-O-(3l-N-desmethyl-3'-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-(benzotriazol-l-yl)-butyl)-imino)]erythromycin A (Compound No. 92), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-l 2, ll-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 93), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,l l-[oxycarbonyl-((4-((4-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 94), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((2-trifluoromethyl)-benzoimidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 95), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-((4,5-diphenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 96), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4,5-diphenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 97), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 98), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl methyl)-! 1,12-dideoxy-3-O-decladinosyl-6-Omethy 1-3-oxo-12,1 l-[oxycarbonyl-((4-((4-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 99), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-cyclopropyl methyl)-! l,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,l l-[oxycarbonyl-((4-(benzotriazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 100), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl methyl)-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-((4-pyridin-3-yl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 101), 2-a-Fluoro-5-0-(3l-N-desmethyl-3'-N-acetyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyrrolo[2,3-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 102), -11- Z-a-Fluoro-S-O-CB'-N-desmethyl-S'-N-acety^-ll.lZ-dideoxy-S-O-decladinosyl-e-O-methyl-B-oxo- 12,1 l-[oxycarbonyl-((4-((4-phenyl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 103), Z-a-Fluoro-S-O-CS'-N-desmethyl-S'-N-acetyO-lUn-dideoxy-S-O-decladinosyl-e-O-methyl-S-oxo- 12,1 l-[oxycarbonyl-((4-((lH)-imidazo[4,5-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 104), 2-a-Fluoro-5-O-(3'-N-desmethyl-3l-N-acetyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3H)-imidazo[4,5-b]pyridin-3-yl)-butyl)-imino)] erythromycin A (Compound No. 105), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3,5-diphenyl)-pyrazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 106), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-((4-pyridn-3-yl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 107), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-2-fluoroethyl)-11,12-dideoxy-3-O-decladinosyl-6-0-methyl- 3-oxo-12,l l-[oxycarbonyl-((4-((lH)-imidazo[4,5-b]pyridin-l-yl)-butyl)-imino)] erythromycin A (Compound No. 108), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3,5-diphenyl)-pyrazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 109), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl methyl)-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3 -oxo-12,11- [oxycarbonyl-((4-(( 1 H)-imidazo [4,5 -b] pyridin-1 -y l)-buty l)-imino)] erythromycin A (Compound No. 110), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-acetyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyridin-3-yl)-imidazo)-l-yl)-butyl)-imino)] erythromycin A (CompoundNo. Ill), 2-a-Fluoro-5-0-(3l-N-desmethyl-3'-N-2-fluoroethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl- 3 -oxo-12,11- [oxycarbonyl-((4-((4-(2,4-difluoro)-phenyl)-imidazol-1 -yl)-butyl)-imino)] erythromycin A (Compound No. 112), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-2-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3- oxo-12,11 -[oxycarbonyl-((4-((4-(2,4-difluoro)-phenyl)-imidazol)-1 -yl)-butyl)-imino)] erythromycin A (Compound No. 113), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-allyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-(2,4-difluoro)-phenyl)-imidazol)-l-yl)-butyl)-imino)3 erythromycin A (Compound No. 114), 2-a-Fluoro-5-0-(3'-N-desmethyl-3l-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-furan-3-yl)-imidazol-l-yl)-butyl)-imino)] erythromycin A (Compound No. 115), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-furan-3-yl)-imidazol-l-yl)-butyl)-imino)] erythromycin A hydrochloride salt (Compound No. 115a), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-phenyl-pyrazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 116), -12- 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyridin-3-yl-lH-imidazol-l-yl)-pentyl)-imino)] erythromycin A (Compound No. 117), 2-cc-Fluoro-5-0-(3 '-N-desmethyl-3'-N-ethyl)-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyridin-4-yl-l-H-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 118)2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyridin-4-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 119), 2-a-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-phenyl-pyrazol-l-yl)-butyl)-imino)) erythromycin A (Compound No. 120), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-((indazol-2-yl)-butyl)-imino))] erythromycin A (Compound No. 121), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((indazol-2-yl)-butyl)-imino))]erythromycin (Compound No. 122), 2-a-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3-pyridin-3-yl-pyrazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 123), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-0-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-((indazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 124), 2-a-Fluoro-5 -0-(3 '-N-desmethyl-3 '-N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyrazin-2-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 125), 2-a-Fluoro-5 -O-(3' -N-desmethyl-3' -N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-thiophen-3-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 126), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-thiophen-3-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 127), 2-cc-Fluoro-5 -O-(3' -N-desmethyl-3' -N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-quinolin-3-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 128), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(indazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 129), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyrimidin-5-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 130), 2-ct-Fluoro-5 -O-(3' -N-desmethyl-3' -N-allyl)-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyrimidin-5-yl-lH-imidazol-l-yl)-butyl)-iniino))] erythromycin A (Compound No. 131), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-furan-2-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 132), -13- 2-a-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-thiophen-2-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 133), 2-a-Fluoro-5 -O-(3' -N-desmethyl-3' -N-ethyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-(4-chloro-phenyl)-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 134), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-(4-chloro-phenyl)-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 135), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyridin-2-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 136), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((4-pyridin-2-yl-lH-imidazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 137),2-ct-Fluoro-5 -O-(3' -N-desmethyl-3' -N-allyl)-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((9-(4-amino-butyl)-9H-purin-6-yl)-imino)] erythromycin A (Compound No. 138), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-((3-pyridin-3-yl-lH-pyrazol-l-yl)-butyl)-imino))] erythromycin A (Compound No. 139), 2-a-Fluoro-5 -O-(3' -N-desmethyl-3' -N-2-fluoroethyl)-11,12-dideoxy-3 -O-decladinosyl-6-0- methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-(4-chloro-phenyl)-1 H-imidazol-1 -yl)-butyl)-imino))] erythromycin A (Compound No. 140), 2-a-Fluoro-5 -O-(3' -N-desmethyl-3' -N-2-fluoroethyl)-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-((4-pyridin-2-yl)-1 H-imidazol-1 -yl)-butyl)-imino))] erythromycin A (Compound No. 141), 2-a-Fluoro-5 -O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-(3H-Imidazo[4,5-b]pyridine-2-yl)-butyl)- imino)erythromycin A (Compound No. 142), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11- [oxycarbonyl-((4-(4-Tetrazol-1 -yl-imidazol-1 -yl)-butyl)-imino)erythromycin A (Compound No. 143), 2-a-Fluoro-5-O-(3 '-N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-( 1 H-Benzoimidazol-2-yl)-butyl)-imino)erythromycin A (Compound No. 144), 2-a-Fluoro-5-0-(3 '-N-desmethyl-3 '-N-ethyl)-desosaminyl-l 1,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-[4-(6-Fluoro-pyridin-3-yl)-imidazol-l-yl]-butyl)- imino)erythromycin A (Compound No. 145), 2-cc-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-(3H-Imidazo[4,5-c]pyridine-2-yl)-butyl) iminoerythromycin A (Compound No. 146), 2-cc-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-(4-[ 1,2,4]Trizol-1 -yl-phenyl)-butyl)-imino)erythromycin A (Compound No. 147), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl-3-oxo-12,11- [oxycarbonyl-((4-(4-Imidazol-1 -yl-phenyl)-butyl)-imino)erythromycin A (Compound No. 148), 2-a-Fluoro-5 -O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-[4-(6-Chloro-pyridin-3-yl)-imidazol-l-yl]-butyl)- imino)erythromycin A (Compound No. 149), 2-a-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-(3-[l-(4-Amino-butyl)-lH-imidazol-4-yl]- phenyl)iminoerythromycin A (Compound No. 150), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-(4-Pyridin-3-yl-thiazol-2-yl)-butyl)-imino)erythromycin A (Compound No. 151), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-(3-[2-(4-Amino-butyl)-thiazol-4-yl] -phenyl)iminoerythromycin A (Compound No. 152), 2-a-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3 -oxo-12,11- [oxycarbonyl-((4-(4-Pyrazol-1 -yl-imidazol-1 -yl)-butyl)-imino)erythromycin A (Compound No. 153), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-([l,4']-Bipyrazolyl-r-yl)-butyl)-imino)erythromycin A (Compound No. 154), 2-a-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,l l-[oxycarbonyl-((4-(4-Imidazol-l-yl-pyrazol-l-yl)-butyl) iminoerythromycin A (Compound No. 155), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,l l-[oxycarbonyl-((4-(4-Pyrazol-l-yl-imidazol-l-yl)-butyl) iminoerythromycin A (Compound No. 156), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-[3,3']Bithiophenyl-5-yl-butyl)-imino)erythromycinA (Compound No. 157), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-[2,3']Bithiophenyl-5'-yl-butyl)-imino)erythromycin A (Compound No. 158), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-(4-Furan-2-yl-thiaophen-2-yl)-butyl)-imino)erythromycin A (Compound No. 159), 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-(4-Oxazol-5-yl-imidazol-l-yl)-butyl)-imino)erythromycin A (Compound No. 160), 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,11 -[oxycarbonyl-((4-(3-Pyrrol-1 -yl-[ 1,2,4]triazol-1 -yl)-butyl) iminoerythromycin A (Compound No. 161), 2-cc-Fluoro-5-O-(3' -N-desmethyl-3' -N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-((4-(5-Thiophen-2-yl-tetrazol-2-yl)-butyl)-imino)erythromycin A (Compound No. 162), -15- 2- imino))] erythromycin A; Mass: m/z 844.54 [M++l] Compound No. 124: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11- [oxycarbonyl-((4-((indazol-1 -yl)-butyl)- imino))]erythromycin A; Mass: m/z 817.52 [M++l] Compound No. 125: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-pyrazin-2-yl-1 H-imidazol-1 -yl)-butyl)- imino))] erythromycin A; Mass: m/z 845.56 [M++l] Compound No. 126: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-1 l,12-dideoxy-3-Odecladinosyl- 6-0-methyl-3-oxo-12,11- [oxycarbonyl-((4-((4-thiophen-3 -yl-1 H-imidazol-1 -yl)- butyl)-imino))] erythromycin A; Mass: m/z 849.45 [M++l] Compound No. 127: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11- [oxycarbonyl-((4-((4-thiophen-3 -yl-1 H-imidazol-1 -yl)- butyl)-imino))] erythromycin A; Mass: m/z 861.45 [M++l] Compound No. 128: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-quinolin-3-yl-1 H-imidazol-1 -yl)- butyl)-imino))] erythromycin A; Mass: m/z 894.60 [M++l] Compound No. 129: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3 -oxo-12,11- [oxycarbonyl-((4-(indazol-1 -yl)-butyl)-imino))] erythromycin A; Mass: m/z 829.49 [M++l] Compound No. 130: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-pyrimidin-5-yl-1 H-imidazol-1 -yl)- butyl)-imino))] erythromycin A; Mass: m/z 845.46 [M++l] Compound No. 131: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-pyrimidin-5-yl-1 H-imidazol-1 -yl)- butyl)-imino))] erythromycin A; Mass: m/z 857.48 [M++l] Compound No. 132: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-furan-2-yl-1 H-imidazol-1 -yl)-butyl)- imino))] erythromycin A; Mass: m/z 833.56 [M++l] Compound No. 133: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-1 l,12-dideoxy-3-Odecladinosyl- 6-0-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-thiophen-2-yl-1 H-imidazol-1 -yl)- butyl)-imino))] erythromycin A; Mass: m/z 849.57 [M++l] Compound No. 134: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-(4-chloro-phenyl)-1 H-imidazol-1 -yl> butyl)-imino))] erythromycin A; Mass: m/z 877.40 [M++l] -68- Compound No. 135: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-(4-chloro-phenyl)-l H-imidazol-1-yl)- butyl)-imino))] erythromycin A; Mass: m/z 889.40 [M++l] Compound No. 136: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-pyridin-2-yl-1 H-imidazol-1 -yl)-butyl)- imino))] erythromycin A; Mass: m/z 844.46 [M++l] Compound No. 137: 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-allyl)-l l,12-dideoxy-3-Odecladinosyl- 6-0-methyl-3-oxo-12,ll-[oxycarbonyl-((4-((4-pyridin-2-yl-lH-imidazol-l-yl)-butyl)- imino))] erythromycin A; Mass: m/z 856.44 [M++l] Compound No. 138: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((9-(4-amino-butyl)-9H-purin-6-yl)-imino)] erythromycin A; Mass: m/z 846.45 [M++l] Compound No. 139: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((3-pyridin-3-yl-1 H-pyrazol-1 -yl)-butyl)- imino))] erythromycin A; Mass: m/z 856.61 [M++l] Compound No. 140: 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-2-fluoroethyl)-l l,12-dideoxy- decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-((4-(4-chloro-phenyl)-lH-imidazol-l-yl)- butyl)-imino))]erythromycin A; Mass: m/z 895.49 [M++l] Compound No. 141: 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-2-fluoroethyl)-l 1,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-pyridin-2-yl)-1 H-imidazol-1 -yl)- butyl)-imino))jerythromycin A; Mass: m/z 862.49 [M++l] Compound No. 142: 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- 0-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(3H-Imidazo[4,5-b]pyridine-2-yl)- butyl)-imino)erythromycin A; Mass: m/z 818.95 [M++l] Compound No. 143: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Tetrazol-1 -yl-imidazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 835.44 [M++l] Compound No. 144: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-( 1 H-Benzoimidazol-2-yl)-butyl)- imino)erythromycin A; Mass: m/z 817.45 [M++l] Compound No. 145: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-[4-(6-Fluoro-pyridin-3-yl)-imidazol-1 - yl]-butyl)-imino)erythromycin A; Mass: m/z 862.39 [M++l] Compound No. 146: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(3H-Imidazo[4,5-c]pyridine-2-yl)- butyl) iminoerythromycin A; Mass: m/z 818.4 [M++l] Compound No. 147: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(4-[l,2,4]Trizol-l-yl-phenyl)-butyl)- imino)erythromycin A; Mass: m/z 844.4 [M++l] Compound No. 148: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Imidazol-1 -yl-phenyl)-butyl)- imino)erythromycin A; Mass: m/z 843.5 [M++l] Compound No. 149: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-[4-(6-Chloro-pyridin-3-yl)-imidazol-lyl]- butyl)-imino)erythromycin A; Mass: m/z 878.4 [M++l] -69- Compound No. 150: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-0-methyl-3-oxo-12,11 - [oxycarbonyl-(3 - [ 1 -(4-Amino-butyl)-1 H-imidazol-4-yl] - phenyl)iminoerythromycin A; Mass: m/z 858.5 [M++l] Compound No. 151: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-11,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(4-Pyridin-3-yl-thiazol-2-yl)-butyl)- imino)erythromycin A; Mass: m/z 861.3 [M++l] Compound No. 152: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-(3-[2-(4-Amino-butyl)-thiazol-4-yl]- phenyl)iminoerythromycin A; Mass: m/z 875.4 [M++l] Compound No. 153: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Pyrazol-1 -yl-imidazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 833.4 [M++l] Compound No. 154: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3 -oxo-12,11 -[oxycarbonyl-((4-( [ 1,4' ] -Bipyrazolyl-1' -yl)-butyl) iminoerythromycin A; Mass: m/z 833.4 [M++l] Compound No. 155: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 - [oxycarbonyl-((4-(4-Imidazol-1 -yl-pyrazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 833.4 [M++l] Compound No. 156: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Pyrazol-1 -yl-imidazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 833.4 [M++l] Compound No. 157: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-[3,3']Bithiophenyl-5-yl-butyl)- imino)erythromycin A; Mass: m/z 865.3 [M++l] Compound No. 158: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-[2,3']Bithiophenyl-5'-yl-butyl)- imino)erythromycin A; Mass: m/z 865.3 [M++l] Compound No. 159: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Furan-2-yl-thiaophen-2-yl)-butyl)- imino)erythromycin A; Mass: m/z 849.4 [M++l] Compound No. 160: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(4-Oxazol-5-yl-imidazol-l-yl)-butyl)- imino)erythromycin A; Mass: m/z 834.4 [M++l] Compound No. 161: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- 0-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(3-Pyrrol-1 -yl-[ 1,2,4]triazol-1 -yl)-butyl) iminoerythromycin A; Mass: m/z 833.4 [M++l] Compound No. 162: 2-cc-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(5-Thiophen-2-yl-tetrazol-2-yl)-butyl)- imino)erythromycin A; Mass: m/z 851.4 [M++l] Compound No. 163: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11- [oxycarbonyl-((4-(4-Tliiophen-3 -yl-pyrazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 849.4 [M++l] Compound No. 164: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Furan-3-yl-pyrazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 833.4 [M++l] Compound No. 165: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Furan-2-yl-pyrazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 833.4 [M+-i-l] Compound No. 166: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(5-Phenyl-tetrazol-2-yl)-butyl)- imino)erythromycin A; Mass: m/z 845.4 [M++l] Compound No. 167: 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-[5-(4-Methoxy-phenyl)-tetrazol-2-yl]- butyl)-imino)erythromycin A; Mass: m/z 875.3 [M++l] Compound No. 168: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(5-Furan-3-yl-imidazol-1 -yl)-butyl)- imino)erythromycin A; Mass: m/z 833.5 [M++l] Compound No. 169: 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,1 l-[oxycarbonyl-((4-(6-Pyrazol-1 -yl-pyridin-3-yl)-butyl)- imino)erythromycin A; Mass: m/z 844.4 [M++l] Compound No. 170: 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(4-Pyridin-3-yl-pyrazol-l-yl)-butyl)- imino)erythromycin A; Mass: m/z 844.5 [M++l] Compound No. 171: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- 0-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(5-Thiophen-2-yl-pyridin-3-yl)-butyl)- imino)erythromycin A; Mass: m/z 860.3 [M""+l] Compound No. 172: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-Phenyl-thiophen-2-yl)-butyl)- imino)erythromycin A; Mass: m/z 859.4 [M++l] Compound No. 173: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-(N-(4-Amino-butyl)-N-thiazol-2-ylnicotinimido)] erythromycin A; Mass: m/z 890.09 [M++l] Compound No. 174: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-(N-(4-Amino-butyl)-N-thiazol-2-ylnicotinimido)] erythromycin A; Mass: m/z 904.4 [M++l] Compound No. 175: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-[4-(6-Pyrrol-1 -yl-pyridin-3-yl)- imidazol-l-yl]-butyl)-imino)erythromycin A; Mass: m/z 909.5 [M++l] Compound No. 176: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- 0-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(6-Pyrrol-l-yl-pyridin-3-yl)-butyl)- imino)erythromycin A; Mass: m/z 834.4 [M++l] Compound No. 177: 2-oc-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- 0-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(2-Pyrrol-1 -yl-thiazol-5-yl)-butyl)- imino)erythromycin A; Mass: m/z 849.3 [M++l] Compound No. 178: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(6-Imidazol-1 -yl-pyridin-3-yl)-butyl)- imino)erythromycin A; Mass: m/z 844.4 [M++l] Compound No. 179: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-[4-(Tetrahydro-furan-2-yl)-pyridin-3- Compound No. 180: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 1 2, 1 1 -[oxycarbonyl-((4-((4-p-tolyl-imidazol- 1 -yl)-butyl)-imino)] erythromycin A; Mass: m/z 857.08[M++1] Compound No. 1 81 : 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-(4-(4-aminophenyl)-imidazol- 1 -yl)-butyl)- imino)] erythromycin A; Mass: m/z 858.07[M++1] Compound No. 182: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-0-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-(4-(4-methyl-3-aminophenyl)-imidazol- 1 - yl)-butyl)-imino)] erythromycin A; Mass: m/z 872.1 [M++l] Compound No. 1 83: 2-a-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-ethyl)- 11,1 2-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 12,1 1 -[oxycarbonyl-((4-((4-(3-imidazol- 1 yl)-phenyl)imidazol- 1 - yl)-butyl)-imino)] erythromycin A; Mass: m/z 909.12[M++1] Compound No. 1 84: 2-a-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-ethyl)- 1 1 , 12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(4-(3-(N,N-dicyclopropyl-amino)-phenyl)- imidazol-l-yl)-butyl)-imino)] erythromycin A; Mass: m/z 938.20[M++1] Compound No. 185: 2-a-Fluoro-5-0-(3 '-N-desmethyl-3' -N-ethyl)- 1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-(4-(3-(N,N-dimethyl-amino)phenyl)- imidazol-l-yl)-butyl)-imino)] erythromycin A; Mass: m/z 886.12[M++1] Compound No. 186: 2-cc-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-ethyl)- 1 1,1 2-dideoxy-3-Odecladinosyl- 6-0-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-((4-(3-(tetrazol- 1 yl)-phenyl)-imidazol- 1 - yl)-butyl)-imino)] erythromycin A; Mass: m/z 911.09[M++1] Compound No. 187: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-((4-(2-(pyrrol- 1 yl)-thiozol-5-yl)-imidazoll- yl)-butyl)-imino)] erythromycin A; Mass: m/z 915.04[M++1] Compound No. 188: 2-a-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-ethyl)- 1 1,1 2-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-((4-(3-trifluoromethyl-phenyl)-imidazol-lyl)- butyl)-imino)] erythromycin A; Mass: m/z 857.08[M++1] Compound No. 189: 2-a-Fluoro-5-O-(3 '-N-desmethyl-3' -N-ethyl)- 1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-((N-(thiazol-2-yl)-benzimido)-butyl)- imino)] erythromycin A; Mass: m/z 903.4[M++1] Compound No. 190: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-0-methyl-3 -oxo-1 2, 1 1 -[oxycarbonyl-((4-(4-(2-arnino-pyrimidin)-5-yl)-imidazol- 1 - yl)-butyl)-imino)] erythromycin A; Mass: m/z 680.04 Compound No. 191 : 2-a-Fluoro-5-O-(3 '-N-desmethyl-3' -N-ethyl)- 1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 12,11- [oxycarbonyl-((4-((4-(4-(pyrrol- 1 yl)-phenyl)-imidazol- 1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 908.13 [M++l] Compound No. 192: 2-a-Fluoro-5-O-(3 '-N-desmethyl-3' -N-ethyl)- 1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 1 2, 1 1 -[oxycarbonyl-((4-((4-(3-(pyrrol- 1 yl)-phenyl)-imidazol- 1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 908.13 [M++l] Compound No. 193: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 1 2, 1 1 -[oxycarbonyl-((4-(4-(3-(N-acetyl-amino)-phenyl)-imidazoll- yl)-butyl)-imino)] erythromycin A; Mass: m/z 900.11[M++1] Compound No. 194: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo- 1 2, 1 1 -[oxycarbonyl-((4-(4-(3-(N-isopropyl-amino)-phenyl)- imidazol-l-yl)-butyl)-imino)] erythromycin A; Mass: m/z 900.15[M++1] Compound No. 195: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-l l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-((4-(3-nitrophenyl)-imidazol-l-yl)-butyl)- imino)] erythromycin A; Mass: m/z 888.05[M++1] Compound No. 196: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(4-(3-(N-benzoyl-amino)-phenyl)- imidazol-l-yl)-butyl)-imino)] erythromycin A; Mass: m/z 962.18[M++1] Compound No. 197: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-((4-(3,4-dimethyl-phenyl)-imidazol-l-yl)- butyl)-imino)] erythromycin A; Mass: m/z 871.11[M++1] Compound No. 198: 5-O-(3'-N-desmethyl-3'-N-ethyl)-l 1,12-dideoxy-3-O-decladinosyl-6-Omethyl- 3-oxo-12,ll-[oxycarbonyl-(((4-(4-Pyridin-3-yl-thiazol-2-yl)-butyl)-imino)] erythromycin A; Mass: m/z 862.4 [M++l] Compound No. 199: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-(4-fluorophenyl)-imidazol-1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 861.05 [M++l] Compound No. 200: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((4-(4-methoxy-phenyl)-imidazol-1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 873.08 [M++l] Compound No. 201: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-1 l,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((N-(benzthiazol-2-yl)-benzimido)-butyl)- imino)] erythromycin A; Mass: m/z 953.19 [M++l] Compound No. 202: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-0-methyl-3-oxo-12,11 -[oxycarbonyl-((4-((N-(thiazol-2-yl)-nicotinamido)-butyl)- imino)] erythromycin A; Mass: m/z 904.12 [M++l] Compound No. 203: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-11,12-dideoxy-3-Odecladinosyl- 6-O-methyl-3-oxo-12,11- [oxycarbonyl-((4-(4-(3-(N-methyl-amino)-phenyl)-imidazoll- yl)-butyl)-imino)] erythromycin A; Mass: m/z 872.10 [M++l] Compound No. 204: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-(4-(2-aminopyridyl)-imidazol-1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 8590.6 [M++l] Compound No. 205: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)desosaminyl-l 1,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(4-(5-(2-aminopyridyl)-2H-tetrazol-5- yl)-butyl)-imino)] erythromycin A; Mass: m/z 861.03 [M++l] Compound No. 206: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-(3,4-difluorophenyl)-imidazol-1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 878.04 [M++l] Compound No. 207: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-(4-(2-chloropyridyl)-imidazol-1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 878.49 [M++l] Compound No. 208: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,11 -[oxycarbonyl-((4-(4-(3-(6-aminopyridyl)-imidazol-1 -yl)- butyl)-imino)] erythromycin A; Mass: m/z 859.06 [M++l] Compound No. 209: 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)desosaminyl-l l,12-dideoxy-3- O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-(5-(2-Chloro-pyridin-4-yl)-tetrazol-2- yl)-butyl)-imino)] erythromycin A; Mass: m/z 880.46[M++1] Example 6. Pharmacological activity Compounds described herein displayed antibacterial activity in vitro especially against strains that are resistant to macrolides either due to efflux (mef strains) or ribosomal modification (erm) strains. These compounds are useful in treating community acquired pneumonia, upper and lower respiratory tract infections, skin and soft tissue infections, hospital acquired lung infections, bone and joint infections, and other bacterial infections, for example, mastitis, catether infection, foreign body, prosthesis infections or peptic ulcer disease. Minimum inhibitory concentration (MIC) has been an indicator of in vitro antibacterial activity widely used in the art. Procedure: Medium a) Cation adjusted Mueller Hinton Agar (MHA-Difco) b) Trypticase Soya Agar (TSA) Inoculum preparation Cultures were streaked on TSA for aerobic cultures and MHA with 5 % sheep blood for fastidious cultures. Aerobic cultures were incubated at 37 °C for about 18-24 hours. Fastidious cultures were incubated CO2 incubation (5% CO2) at 37 °C for about 18-24 hours. Three to four well-isolated colonies were taken and saline suspensions were prepared in sterile densimat tubes. The turbidity of the culture was adjusted to 0.5-0.7 Me Farland standard (1.5 x 108 CFU/mL). The cultures were diluted 10 fold in saline to obtain inoculum sizes of approximately 1-2 x 107 organisms/mL. Preparation of drug concentration 1 mg/mL concentration of stock solution of drugs was prepared in dimethylsulfoxide/distilled water/solvent given in National Committee for Clinical Laboratory Standards (NCCLS) manual. Serial two-fold dilutions of the compounds and standard drugs were prepared as per NCCLS manual. The stock solution was changed according to the need of the experiment. Preparation of Agar Plates Two mL of respective drug concentration was added to 18 mL of Molten Mueller Hinton agar to achieve the required range, for example 0.015 ug/mL - 16 jxg/mL. For fastidious cultures 1 mL of sheep blood was added in Molten Mueller Hinton agar. MHA and MHA with 5% sheep blood plates without antibiotic for each set were prepared for controls. One MHA and MHA with 5% sheep blood plate without antibiotic for determining quality check for media was prepared. Preparation of Teflon template 1 μL of each culture on each plate was replicated with the help of a replicator (i.e., Denley's multipoint replicator). The spots were allowed to dry and the plates were incubated for about 18-24 hours at 37 °C. Fastidious cultures were incubated at 37 °C in a CO2 incubator. The results were noted comparing with the control plates. Endpoint definition The concentration of drug at which there was complete disappearance of growth spot or formation of less than 10 colonies per spot was considered as Minimum Inhibitory Concentration (MIC). The MICs of Quality Control (QC) strains were plotted on the QC chart for agar dilution method. If the MICs were within the range, the results interpreted by comparing MICs of standards against all organisms with those of test compounds. Precautions & Quality Control Measures Quality Control Strains Staphylococcus aureus ATCC 29213 Enterococcus faecalis ATCC 29212 Eschericia coli ATCC 25922 Pseudomonas aeruginosa ATCC 27853 All 60 cultures were visually checked for purity. Media Control: NCCLS disc diffusion assay using 10 μg discs of Gentamicin (Difco) against Pseudomonas aeruginosa ATCC 27853. A zone diameter of 16-21 mm was considered for optimum cation (Magnesium and Calcium) content of the media. The diameter was plotted in the media QC chart. References: o National Committee for Clinical Laboratory Standards (NCCLS), Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically - Fifth Edition; Approved Standard. M7-A5, Vol.20. No. 2 (January 2000). o National Committee for Clinical Laboratory Standards, Performance Standards for Antimicrobial Susceptibility Testing - Twelfth informational supplement, M 100-12, Vol. 22 No. 1 (January 2002). Results: a) The compounds described herein exhibited MIC values against Staphylococcus aureus in the range of between about 0.03 (μg/mL to about 8 μg/mL, for example between about 0.03 μg/mL to about 1 μgmL. b) The compounds described herein exhibited MIC values against sensitive Streptococcus pneumoniae in the range of between about 0.008 ng/mL to about 16 ng/mL, for example between about 0.008 ug/mL to about 0.5 ug/mL. c) The compounds described herein exhibited MIC values against erythromycin resistant Streptococcus pneumoniae in the range of between about 0.06 μg/mL to about 16 ug/mL, for example between about 0.06 (j.g/mL to about 4 ug/mL. d) The compounds described herein exhibited MIC values against Haemophilus injluenzae in the range of between about 0.03 |μg/mL to about 32 μg/mL, for example between about 0.03μg/mL to about 16μg/mL. e) The compounds described herein exhibited MIC values against Moraxella species in the range of between about 0.004 ug/mL to about 4 μg/mL, for example between about 0.004 ug/mL to about 1 ug/mL. f) The compounds described herein exhibited MIC values against telithromycin resistant Streptococcus pneumoniae in the range of between about 0.5 ug/mL to about 16 μg/mL, for example between about 0.5 ug/mL to about 16 ug/mL. g) The compounds described herein exhibited MIC values against sensitive Streptococcus pyogenes in the range of between about 0.008 ng/mL to about 1 ug/mL, for example between about 0.008 |ig/mL to about 0.15 ug/mL. h) The compounds described herein exhibited MIC values against erythromycin resistant Streptococcus pyogenes in the range of between about 0.015 μg/mL to about 16 μg/mL, for example between about 0.015 μg/mL to about 16 i) The compounds described herein exhibited MIC values against methicillin resistant Staphylococcus aureus to about 16 ug/mL. -76- j) The compounds described herein exhibited MIC values against sensitive Enterococci species in the range of between about 0.03 μg/mL to about 1 ug/mL, for example between about 0.03 ug/mL to about 0.5 ug/mL. k) The compounds described herein exhibited MIC values against resistant Enterococci species in the range of between about 1 ug/mL to about 16 μg/mL, for example between about 1 μg/mL to about 16 μg/mL. WE CLAIM: 1. A compound having the structure of Formula I, Formula I or a pharmaceutically acceptable salt, pharmaceutically acceptable solvate, enantiomer, diastereomer or polymorph thereof, wherein: R1 is hydrogen or a hydroxyl protecting group; R2 and R3 are independently alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocycle, aralkyl, (heterocycle)alkyl or COR11, wherein R11 is hydrogen, alkyl or aralkyl, with the proviso that R2 and R3 are not simultaneously methyl; W is alkenyl, -G(CH2)qJ-, -CR9R10, -NR9- or -S02, wherein q is an integer of from 2 to 6; G is no atom, -CO, -CS or -S02; R9 and R10 are independently hydrogen or alkyl; and J is no atom, -CR9R10 or N(R12)(CH2)m, wherein m is an integer of from 0 to 6; R9 and R10 are the same as defined earlier; and R12 is hydrogen, alkyl, alkylene, alkynyl, COR8 or - o n (CH2)m-R , wherein R is alkyl, aryl or heterocycle; R is aryl or heterocycle; R4 is alkyl, alkenyl or alkynyl; R' is alkyl or -(CH2)r-U, wherein r is an integer of from 1 to 4 and U is alkenyl or alkynyl; and Y is halogen, cyano or alkyl; Z is oxygen, sulfur or NOR11, wherein R11 is the same as defined earlier. 2. A compound of claim 1, wherein R is heterocycle; R2 is methyl; R3 is alkyl (except methyl), alkenyl, cycloalkyl or COR11; W is -G(CH2)qJ- or CR9R10, wherein G, q, J, R9, R10 and R11 are the same as defined in claim 1. Claims 3. A compound of claim 1, wherein R1 is hydrogen or a hydroxy protecting group (wherein the hydroxy protecting is benzoyl, tetrahydropyranyl or a trialkylsilyl- ether); R2 is CH3; R is C2H5, -CH2-CH=CH2 or -CH2CH2F; W is -(CH2)4-J- wherein J is CH2 or (CH2)0-i-N(CO)- Ra;and Ris wherein Xi-X3 are independently CH or N; X4-X8 are independently CH, CR4 or N; X9 is O, S, N, NH or CH; Xio is NH or S; Ra is thienyl, furyl, pyrazolyl, oxazolyl, tetrazolyl, imidazolyl, pyridinyl, fluoropyridinyl, chloropyridinyl, aminopyridinyl, pyrazinyl, pyrimidinyl, aminopyrimidinyl, quinolinyl, pyrrolo-pyridyl, pyrrolo-thiazolyl or optionally substituted phenyl; R'a is hydrogen or furyl; Rb is hydrogen or amino; RC is hydrogen, thienyl, furyl, pyrazolyl,pyrazinyl, pyridinyl, aminopyridinyl, pyrimidinyl, pyrrolyl, imidazolyl or optionally substituted phenyl; and Rd is thienyl, pyrazolyl, imidazolyl, triazolyl, pyrrolyl or tetrahydrofuryl. 4. A compound selected from: 2-a-Fluoro-5 -O-(3 '-N-desmethyl-3 '-N-ethy l)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,11- [oxycarbonyl-((3-(imidazol-l-yl)-propyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(lH-imidazo[4,5-b]-pyridin-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(3H-imidazo[4,5-b]-pyridin-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(benzoimidazol-1 -yl)-butyl)-itnino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(imidazol-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladi- nosyl-6-0-methyl-3-oxo- 12,1 l-[oxycarbonyl-((3-(imidazol-l-yl)-propyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladi- 12,1 l-[oxycarbonyl-((3-(imidazol-l-yl)-propyl)-imino)] erythromycin A, nosyl-6-O-methyl-3-oxo- 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-propyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((3-(imidazol-l-yl)-propyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-propyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyrrolo-[2,3-b]pyridin-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(pyrrolo-[2,3-b]pyridin-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-isopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(benzoimidazol-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,11 -[oxycarbonyl-((4-(benzoimidazol-1 -yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-n-propyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(imidazol-l-yl)-butyl)-imino)]erythromycin A, 2-cc-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,11- [oxycarbonyl-((4-(pyrrolo-[2,3-b]pyridin-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-isopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(lH-imidazo[4,5-b]-pyridin-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5 -O-(3 '-N-desmethyl-3 '-N-ethyl)-desosaminyl-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3 -oxo-12,11- [oxycarbonyl-((4-(purin-9-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-cyclopropyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,ll-[oxycarbonyl-((4-(3H-imidazo[4,5-b]-pyridin-3-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5 -0-(3 '-N-desmethyl-3 '-N-ethy l)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-l 2,11 - [oxycarbonyl-((4-(4-(pyridin-3-yl)-imidazol-l-yl)-butyl)-imino)]erythromycin A, 2a-Fluoro-5-O-(3 '-N-desmethyl-3'-N-ethyl)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl-3 -oxo-12,11- [oxycarbonyl-(((N'-methyl-N'-quinolin-4-ylmethyl)-2-aminoethyl)-imino)]erythromycin A, 2-a-Fluoro-5 -0-(3 '-N-desmethyl-3'-N-ethy l)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl-3 -oxo-12,11 - [oxycarbonyl-(((N'-methyl-N'-pyridine-3-ylmethyl)-2-aminoethyl)-imino)]erythromycin A, 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-(((N'-methyl-N-pyridine-4-ylmethyl)-2-aminoethyl)-imino)]erythromycin A, 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-(((N'-methyl-N'-pyridine-2-ylmethyl)-2-aminoethyl)-imino)]erythromycin A, 2-] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(quinolin-3-yl)-lH-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll-[oxycarbonyl-((4-( 1 H-indazol-1 -yl)-butyl)-imino)] erythromycin A,2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(pyrimin-5-yl)-lH-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbQnyl-((4-(4-(pyrimin-5-yl)-lH-imidazol-l-yl)-butyl)-imino)]erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(furan-2-yl)-lH-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3>-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(thiophen-2-yl)-lH-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-0-(3 '-N-desmethyl-3 '-N-ethyl)-desosaminyl-l 1,12-dideoxy-3-O-decladinosyl-6-0-methyl-3-oxo-12,11- [oxycarbonyl-((4-(4-(4-chloro-phenyl)-1 H-imidazol-1 -yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,lltoxycarbonyl-(( 4-(4-(4-chloro-phenyl)-lH-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-0-(3' -N-desmethyl-3 '-N-ethyl)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl-3-oxo-12,11- [oxycarbonyl-((4-(4-(pyridin-2-yl)-1 H-imidazol-1 -yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5 -0-(3 '-N-desmethyl-3 '-N-allyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3 -oxo-12,11- [oxycarbonyl-((4-(4-(pyridin-2-yl)-lH-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-allyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((9-(4-amino-butyl)-9H-purin-6-yl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-allyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(pyridin-3-yl)-lH-pyrazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-fluoroethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-(4-(4-chloro-phenyl)-lH-imidazol-1-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-2-tluoroethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo- 12,1 l-[oxycarbonyl-((4-(4-(pyridin-2-yl)-lH-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(3H-imidazo[4,5-b]pyridine-2-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,11 - [oxycarbonyl-((4-(4-(tetrazol-l-yl)-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-0-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(lH-benzoimidazol-2-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyI)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(6-fluoro-pyridin-3 -yl)-imidazol-1 -yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(3H-imidazo[4,5-c]pyridine-2-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-([l,2,4]trizol-l-yl)-phenyl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(imidazol-l-yl)-phenyl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll, 12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12.il- [oxycarbonyl-((4-(4-(6-chloro-pyridin-3-yl)-imidazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-(3-(l-(4-aminobutyl)-lH-imidazol-4-yl)-phenyl)imino] erythromycin A, 2-cx-Fluoro-5-O-(3' -N-desmethyl-3 '-N-ethyl)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl-3 -oxo-12,11- [oxycarbonyl-((4-(4-(pyridin-3-yl)-thiazol-2-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5 -0-(3' -N-desmethyl-3 '-N-ethyl)-desosaminyl-11,12-dideoxy-3 -O-decladinosyl-6-O-methyl-3-oxo-12,11- [oxycarbonyl-(3 -(2-(4-aminobutyl)-thiazol-4-yl)-phenyl)imino] erythromycin A, -85- 2-a-FIuoro-5-O-(3'-N-desmethyl-3 '-N-ethyI)-desosaminyl-l 1,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,l 1- [oxycarbonyl-((4-(4-(pyrazol-1 -yl)-imidazol-l -yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-([l,4']-bipyrazolyl-l '-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,lltoxycarbonyl-(( 4-(4-(imidazol-l-yl)-pyrazol-l-yl)-butyl)-imino)] erythromycin A, 2-a-FIuoro-5-O-(31-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-(4-(pyrazol-1 -yl)-imidazol-1 -yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3'-N-desmethyl-3'-N-ethyl)-desosaminyl-ll,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,ll- [oxycarbonyl-((4-([3,3']bithiophenyl-5-yl)-butyl)-imino)] erythromycin A, 2-a-Fluoro-5-O-(3 '-N-desmethyl-3 '-N-ethyl)-desosaminyl-11,12-dideoxy-3-O-decladinosyl-6-O-methyl-3-oxo-12,11 - [oxycarbonyl-((4-([2,3 ']bithiophenyl-5'-yl)-buty l)-imino)] erythromycin A, 2-