FIELD OF THE INVENTION The present invention relates to novel oxazole derivatives of tetracyclines which are useful as antibiotic agents and exhibit antibacterial activity against a wide spectrum of organisms including organisms which are resistant to tetracyclines and other antibiotics. This invention also relates to novel tetracycline intermediates useful for making the novel compounds and novel methods for producing the novel compounds and the intermediate compounds. BACKGROUND OF THE INVENTION Since 1947 a variety of tetracycline antibiotics have been synthesized and described for the treatment of infectious diseases in man and animals. Tetracyclines inhibit protein synthesis by binding to the 30S subunit of the bacterial ribosome preventing binding of aminoacyl FtNA (Chopra, Handbook of Experimental Pharmacology, Vol. .78, 317-392, Springer-Verlag, 1985). Resistance to tetracyclines has emerged among manycliriically important microorganisms which limit the utility of these antibiotics. There are two major mechanisms of bacterial resistance to tetracyclines: a) energy-dependent efflux of the antibiotic mediated by proteins located in the cytoplasmic membrane which prevents intracellular accumulation of tetracycline (S. B. Levy, et al., Antimicrob. Agents Chemotherapy 33, 1373-1374 (1989); and b) ribosomal protection mediated by a cytoplasmic protein which interacts with the ribosome such that tetracycline no longer binds or inhibits protein synthesis (A. A. Salyers, B. S. Speers and N. B. Shoemaker, Mol. Microbiol, 4:151-156,1990). The efflux mechanism of resistance is encoded by resistance determinants designated tetA-tetL. They are common in many Gram-negative bacteria (resistance genes Class A-E), such as Enterobacteriaceae, Pseudomonas, Haemophilus and Aeromonas, and in Gram- positive bacteria (resistance genes Class K and L), such as Staphylococcus, Bacillus and Streptococcus. The ribosomal protection mechanism of resistance is encoded by resistance determinants designated TetM, N and O, and is common in Staphylococcus, Streptococcus, Campylobacter, Gardnerella, Haemophilus and Mycoplasma (A. A. Salyers, B. S. Speers and N. B. Shoemaker, Mol. Microbiol, 4:151-156 1990). A particularly useful tetracycline compound is 7-(dimethylamino)- 6-demethyl-6- deoxytetracycline, known as minocycline (see U.S. Pat. No. 3,148,212, U.S. Pat. No. RE 26,253 and U.S. Pat. No. 3,226,436 discussed below). However, strains harboring the tetB (efflux in gram-negative bacteria) mechanism, but not tetK (efflux in Staphylococcus) are resistant to minocycline. Also, strains carrying tetM (ribosomal protection) are resistant to minocycline. This invention describes the synthesis of novel tetracycline compounds which demonstrate significant in vitro and in vivo activity vs. tetracycline and minocycline susceptible strains and some tetracycline and minocycline resistant strains, that is, those harboring the tetM (ribosomal protection) resistance determinants. Duggar, U.S. Pat. No. 2,482,055, discloses the preparation of Aureomycin.RTM. by fermentation which have antibacterial activity. Growich et al., U.S. Pat. No. 3,007,965, disclose improvements to the fermentation preparation. Beereboom et al., U.S. Pat. No. 3,043,875 discloses tetracycline derivatives Boothe et al., U.S. Pat. No. 3,148,212, reissued as U.S. Pat. No. RE 26,253, and Petisi et al., U.S. Pat. No. 3,226,436, discloses tetracycline derivatives which are useful for treating bacterial infections. Blackwood et al., U.S. Pat. No. 3, 200,149 discloses tetracycline derivatives which possess microbiological activity. Petisi et al., U.S. Pat. No. 3,338,963 discloses tetracycline compounds which have broad-spectrum antibacterial activity. Bitha et al., U.S. Pat. No. 3,341,585 discloses tetracycline compounds which have broad-spectrum antibacterial activity. Shu, U.S. Pat. No. 3,360,557 discloses 9- hydroxytetracyclines which have been found to possess antibacterial activity. Zambrano, U.S. Pat. No. 3,360,561 discloses a process for preparing 9-nitrotetracyclines. Martell et al., U.S. Pat. No. 3,518,306 discloses tetracyclines which possess in vivo antibacterial activity. In U.S. Pat. No. 5,021,407 a method of overcoming the resistance of tetracycline resistant bacteria is disclosed. The method involves utilizing a blocking agent compound in conjunction with a tetracycline type antibiotic. This patent does not disclose novel tetracycline compounds which themselves have activity against resistant organisms. Described in U.S. Pat. No. 5,494,903 are 7-substituted-9- substitutedamino-6-demethyl-6-deoxytetracyclines which have broad spectrum antibacterial activity. In summary, none of the above patents teach or suggest the novel compounds of this application. In addition, none of the above patents teach or suggest novel tetracycline compounds of the invention having activity against tetracycline and minocycline resistant strains as well as strains which are normally susceptible to tetracyclines. SUMMARY OF THE INVENTION In accordance with the present invention, there is provided compounds represented by Formula (I); wherein: X is selected from hydrogen, amino, NR11R12, alkyl of 1 to 12 carbon atoms optionally substituted , aryl of 6,10 or 14 carbon atoms optionally substituted, vinyl optionally substituted, alkynyl of 2 to 12 carbon atoms optionally substituted and halogen; A" is a moiety selected from the group: R11 and R12 are each independently H or alkyl of 1 to 12 carbon atoms or Ft11 and Ft12 when optionally taken together with the nitrogen atom to which each is attached form a 3 to 7 mernbered saturated hydrocarbon ring; Y is selected from hydrogen, alkyl of 1 to 12 carbon atoms optionally substituted, aryl of 6, 10 or 14 carbon atoms optionally substituted, alkenyl of 2 to 12 carbon atoms optionally substituted, vinyl, alkynyl of 2 to 12 carbon atoms optionally substituted and halogen; R is selected from alkyl of 1 to 12 carbon atoms optionally substituted, alkenyl of 2 to 12 carbon atoms optionally substituted, alkynyl of 2 to 12 carbon atoms optionally substituted, -CH2NR1R2, aryl of 6,10 or 14 carbon atoms optionally substituted, aralkyl of7 to 16 carbon atoms optionally substituted, aroyl of 7 to 13 carbon atoms optionally substituted, SR3, heteroaryl of 5 or 6 ring atoms optionally substituted, containing 1 to 4 heteroatoms which may be the same or different, independently selected from nitrogen, oxygen and sulfur, and heteroarylcarbonyl of 5 or 6 ring atoms optionally substituted containing 1 to 4 heteroatoms which may be the same or different,, independently selected from nitrogen, oxygen and sulfur; R1 and R2 are each independently H or alkyl of 1 to 12 carbon atoms or R1 and R2 when optionally taken together with the nitrogen atom to which each is attached form a 3 to 7 membered saturated hydrocarbon ring; R3 is alkyl of 1 to 12 carbon atoms optionally substituted, -CH2-aryl optionally substituted, aralkyl of 7 to 16 carbon atoms optionally substituted, aroyl, -CH2(CO)0CH2aryI optionally substituted, -CH2-alkenyl of 2 to 12 carbon atoms optionally substituted, and -CH2-alkynyl of 2 to 12 carbon atoms optionally substituted; with the provisos that when X is NR1R2 and R1 is hydrogen, then R2 is methyl, ethyl, n-propyl, n-butyl, 1-methylethyl, 1 -methylpropyl, 2-methylpropyl or 1,1-dimethylethyl; and that when R1 is methyl or ethyl then R2 is methyl, ethyl, n-propyl, 1-methylethyl, n-propyl, 1-methylpropyl, or 2-methylpropyl; or a tautomer or pharmaceutically acceptable salts thereof. Definitions The term alkyl as a group or part of a group means a straight or branched alkyl moiety of 1 to 12 carbon atoms which can be optionally independently substituted with 1 to 3 substituents selected from the group halogen, amino, cyano, cycloalkyl of 3 to 6 carbon atoms, alkyl of 1 to 12 carbon atoms, aryl optionally substituted, phenyl, hydroxyl, alkoxy of 1 to 12 carbon atoms, NH-alkyl of 1 to 12 carbon atoms, N- cycloalkyl of 3 to 6 carbon atoms, NH-(alkyl of 1 to 12 carbon atoms)-aryl optionally substituted and heterocyclyl of 3 to 8 membered ring. In some embodiments of the invention alkyl is a moiety of 1 to 6 carbon atoms. In other embodiments of the invention alkyl is a moiety of 1 to 3 carbon atoms. In other embodiments alkyl is substituted by heterocyclyl of 4 to 7 ring members (e.g. pyrrolidinyl) The term alkenyl means a straight or branched carbon chain of 2 to 12 carbon atoms having at least one site of unsaturation optionally independently substituted with 1 to 3 substituents selected from the group optionally substituted aryl, phenyl, heteroaryl, halogen, amino, cyano, alkyl of 1 to 12 carbon atoms, hydroxyl, and alkoxy of 1 to 12 carbon atoms. The term vinyl means a moiety CH2=CH-. As used herein the term alkoxy as a group or part of a group refers to alkyl-O- wherein alky) is hereinbefore defined. As used herein the term aryl as a group or part of a group, e.g., aralkyl, aroyl, means an aromatic moiety having 6,10 or 14 carbon atoms preferably 6 to 10 carbon atoms, which can be optionally substituted with 1 to 3 substituents independently selected from halogen, nitro, cyano, alkenyl, hydroxyl, alkyl, haloalkyl, alkoxy, benzyloxy, amino, alkylamino, dialkylamino, carboxyl, alkoxycarbonyl, methylenedioxy and phenyl. In particular, aryl is phenyl or naphthyl optionally substituted with 1 to 3 substituents. Substituted phenyl may optionally be the moiety The term aralkyl as used herein of 7,to 16 carbon atoms means an alkyl substituted with an aryl group in which the aryl and alkyl group are previously defined. Non- limiting exemplary aralkyl groups include benzyl and phenethyl and the like. Phenyl as used herein refers to a 6-membered carbon aromatic ring. As used herein the term alkynyl includes both straight chain and branched moieties containing 2 to 12 carbon atoms having at least one carbon to carbon triple bond optionally substituted with 1 to 3 substituents independently selected from the group halogen, amino, cyano, alkyl of 1 to 12 carbon atoms, hydroxyl, and alkoxy of 1 to 12 carbon atoms. As used herein the term halogen or halo means F, CI, Br or I. As used herein the term cycloalkyl means a saturated monocyclic ring having from 3 to 6 carbon atoms. Exemplary cycloalkyl rings include but are not limited to cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. In an embodiment of the invention cycloalkyl is a moiety of 5 or 6 carbon atoms. As used herein, R1 and R2 and R11 and R12 when optionally taken together with the nitrogen atom to which each is attached form a 3 to 7 membered saturated hydrocarbon ring, where a non-limiting example is pyrrolidinyl, The term aroyl means an aryl-C(O)- group in which the aryl group is as previously defined. Non-limiting examples include benzoyl and naphthoyl. The term heteroaryl means an aromatic heterocyclic, monocyclic ring of 5 or 6 ring atoms containing 1 to 4 heteroatoms independently selected from O, N and S. Heteroaryl rings may optionally be substituted with 1 to 3 substitutents selected from the group halogen, cyano, nitro, hydroxy, amino, alkylamino, dialkylamino, alkoxy, aryloxy, -CH2OCOCH3 and carboxy. Non-limiting heteroaryl moieties optionally substituted include: furanyl, thienyl, pyl]dyl, tetrazolyl, imidazo, thiazolyl and the like. Further included are benzofuranyl, benzothienyl and quinolinyl. The term heteroarylcarbonyl means a heteroaryl-C(O)- group in which the heteroaryl group is as previously defined. The term heterocyclyl as used herein represents a saturated 3 to 8 membered ring containing one to three heteroatoms selected from nitrogen, oxygen and sulfur. Representative examples are pyrrolidyl, piperidy), piperazinyl, morpholinyl, thiomorpholiny], aziridinyl, tetrahydrofuranyl and the like. The term alkylheterocyclyl means an alkyl-heterocyclyl group in which the alkyl and heterocyclyl group are previously defined. Non-limiting exemplary alkylheterocyclyl groups include moieties of the formulae: Some of the compounds of formula (I), may also exist in their tautomeric forms. Such forms although not explicitly indicated in the above formula are intended to be included within the scope of the present invention. For instance, compounds of formula (I) which exist as tautomers are depicted below: One embodiment of this invention is where R of Formula (I) is selected from the group alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, and alkyl- (heterocyclyl) selected from moieties.of the group Another embodiment of the invention is where R of Formula (I) is phenyl optionally substituted with 1 to 3 substituents. In a preferred embodiment R is selected from moieties of the group A further preferred embodiment of the invention is where R is heteroaryl. In a preferred embodiment R is selected from moieties of the group An additional embodiment of the invention is where R is alkyl of 1 to 6 carbon atoms optionally substituted, alkenyl of 2 to 6 carbon atoms optionally substituted, NH(cycloalkyl of 5 to 6 carbon atoms), NH(alkyl of 1 to 6 carbon atoms) and NH(alkyl of 1 to 6 carbon atoms)-aryl optionally substituted. In a preferred embodiment R is selected from moieties of the group An additional embodiment of the invention is where R of Formula (I) is S-alkyl of 1 to 12 carbon atoms, S-CH2-aryl optionally substituted and S-CH2(CO)OCH2aryl optionally substituted. In a preferred embodiment R is selected from moieties of the group Preferred compounds of the invention include those selected from the group: (6aR,7aS,8S,11aS)-5l8-bis(dimethylamino)-2-(2,2-diphenyIvinyl)-9,11a,12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide, (7aS,8S,11 aS)-8-(dimethylamino)-9,11 a,13-trihydroxy-2-(2-methyl-l -propeny))- 11,12-dioxo-7,7a,8,11,11 a, 12-hexahydronaphthaceno[2,1 -d][1,3]oxazole-10- carboxamide, (6aR,7aS,8S,11aS)-2-tert-butyl-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13- dioxo-6,6a,7,7a,8,11,1 "I a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(E)-2-(2-furyl)ethenyl]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-[(E)-2- phenylethenyl]-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxamide, (eaR.TaS.S^HaSJ-S.a-bisfdimethylaminoJ-g.Ha.^-trihydroxy^-^f)^^- methoxyphenyl)ethenyl]-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotefraceno[2,1 - d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S, 11 aS)-5,8-bis(dimethylamino)-9,11 a, 12-trihydroxy-2-[(E)-2-(3- methoxyphenyl)ethenyl]-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-2-[(E)-2-(2- methoxyphenyl)ethenyl]-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aSl8S,11aS)-5,8-bis(dimethylamino)-2'[(E)-2-(4-fluorophenyl)ethenyl]- 9,11 a, 12-trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13:octahydrotetraceno[2,1 - d][1,3]oxazole-10-carboxamide, (6aR,7aS,85,11aS)-5,8-bis(drmethylamino)-2-[(E)-2-(2-fluorophenyl)etheny)]- 9,11 a, 12-trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetracenof2,1 - d]f1,3Joxazole-10-carboxamide, (6aR,7aS,8S,11aS)-2-(chloromethyl)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-dJ[1,3]oxazole-10- carboxamide, (6aR,7aS,8S,1iaS)-5,8-bis(dimethylamino)-2-[(dimethylamino)methyl]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydroletraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S, 11 aS)-5,8-bis(dimethylamino)-9,11 a, 12-trihydroxy-11,13-dioxo-2- (pyrrolidin-1-yfmethyl)-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- [(propylaminoJmethylj-e.ea.y.Ta.a.H.lla.ia-octahydrotetracenop.l-dJtl.Sloxazole- 10-carboxamide, (eaRJaS.SS.IIaSJ^-KbutylaminoJmethyll-S.a-bisfdimethylamino)^,!^,^- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- [(propylamino)methyl]-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide and (6aR,7aS,8S,11aS)-2-[(terf-butylamino)methyl]-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide. Preferred compounds of the invention include those selected from the group: (7aS,8S,11aS)-8-(dimethylamino)-2-[4-(dimethylamino)phenyl]-9,11a,13-trihydroxy- 11,12-dioxo-7,7a,8,11,11a,12-hexahydronaphthaceno[2,1-d][1,3]oxazole-10- carboxamide, (6aR,7aS,8S,11aS)-2-fe/r-butyl-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13- dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1-d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S, 11 aS)-5,8-bis(dimethylamino)-9,11 a, 12-trihydroxy-2-(4-methylphenyl)- 11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide, (7aS,8S,11aS)-5,8-bis(dimethylamino)-2-(3-fluorophenyl)-9l11a,13-trihydroxy-11,12- dioxo-7,7a,8,11,11 a,12-hexahydrotetraceno[2,1 -d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-2-(4-cyanophenyl)-5,8-bis(dimethylamino)-9I11a,12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide, (6aR,7aS,8S,11 aS)-5I8-bis(dimethylamino)-2-[4-(dimethylamino)phenyl]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-2-(5-tert-butyl-2-hydroxyphenyl)-5,8-bis(dimethylamino)- 9,11 a,12-trihydroxy-11,13-dioxo-6,63,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 - d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-2-[4-(benzyloxy)phenyl]-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11 aS)-2-(2,4-dihydroxyphenyl)-5,8-bis(dimethylamino)-9,11 a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aRl7aS,8S,11aS)-5,8-bis(dimethylamino)-2-(3-fluoro-4-methoxyphenyl)-9,11a,12- trihydroxy-11,13^0X0-6,63,7,73,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-2-(1,3-benzodioxol-5-yl)-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-dj[1,3]oxazole- ■ i 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- (2,4,6-irimethoxyphenyi)-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- (Z^.S-triethoxyphenyl-e.ea.TJa.S.n.lla.lS-octahydrotetracenop.l-dlfl.Sjoxazole- 1O-carboxamide, (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy-2-(1 -methyl-1 H- indol-2-yl)-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11 aS)-2-(4-ferf-butylphenyl)-5,8-bis(dimethylamino)-9,11 a,12- trihydroxy-11,13-dioxo-6,6a,7,7a;8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide and (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-2-[4-(hexyloxy)phenyl]-9,11 a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide. Preferred compounds include those selected from the,group: (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-thien- 3-yl-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-2-(1-benzofuran-2-yl)-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrptetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-2-(2-furyl)-9,11 a,12-trihydroxy-11,13- ' dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10-carboxamide, {5-[(6aR,7aS,8S, 11 aS)-10-(aminocarbonyl)-5,8-bis(dimethylamino)-9,11 a, 12- trihydroxy-11,13-^0X0-6,68,7,73,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazol-2- yl]-2-furyl}rnethyl acetate, (6aR,7aS,8S,1.1 aS)-2-(1-bpnzothien-3-yl)-5,8-bis(dimethylamino)-9,11 a,12- trihydroxy-11,13-dioxo-6,6a,7,73,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino>9,11a,12-trihydroxy-11,13-dioxo-2-(1,3- thiazol-2-yl)-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide, (6aR,7aS,85,11 aS)-5,8-bis(dimethyfamino)-9,11 a, 12-trihydroxy-11,13-dioxo-2- pyl]din-4-yI-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1-d][1,3]oxazo!e-10- carboxamide and (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11 a, 12-trihydroxy-11,13-dioxo-2- pyl]din-3-yl-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazo!e-10- carboxamide. An additional embodiment of the invention is a process for the preparation of a compound of the formula or a pharmaceutically acceptable salt thereof wherein: X is selected from hydrogen, am/no, NR1R2, a/kyl of 1 to 12 carbon atoms optionally substituted., aryl of 6,10 or 14 carbon atoms optionally substituted, vinyl optionally substituted, aJkynyl of 2 to 12 carbon atoms optionally substituted and hafogen; . R' and R2 are each independently H or alkyl of 1 to 12 carbon atoms or V c. hydrolyzing the substituted amine with acid to give a compound of the formula and d. isolating the compound or a pharmaceutically acceptable salt thereof. In a preferred embodiment of the process X is N(CH3)2and the amine R1R2NH is t- butyl amine. In a preferred embodiment of the process the compound [4S-(4a,4aa,5aa,12aa)]- 4,7-Bis(dimethylamino)-9-[2-(1,1-dimethylethylamino)acetylamino]- 1A4a,5,5a,6,11,12a<>ctahydro-3,10,12J2a-tetrahydroxy-1J17 ■ HCI, 608.2038; found (ESI-), 571.21905; EXAMPLE 6 (7aS,8Sl11aS)-5,8-bis(dimethylamino)-2-(3-fluorophenyl)-9,11a,13-trihydroxy-11,12- dioxo-77a,8J1,11a,12-hexahydrotetraceno[2,1-d][1,3]oxazole-10-carboxamide EXAMPLE 7 (6aR,7aS,8S,11aS)-2-(4-cyanophenyl)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxamide MS (ESI) m/z 584.4 (M+H); HRMS: calcd for CaiHagNgCv • HCI, 619.1834; found (ESI-), 582.19817; EXAMPLE 8 (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-2-[4-(dimethylamino)phenyl]-9,11 a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide MS (ESI) m/z 602.2 (M+H); MS (ESI) m/z 301.8 (M+2H); HRMS: calcd for CszHasNsCV ■ HCI, 637.2303; found (ESI-), 600.24521; EXAMPLE 9 (6aR,7aSl8S,11aS)-5,8-bis(dimethylamino)-2-(2,2-diphenylvinyl)-9,11a>12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11 a; 13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide MS (ESI) m/z 661.3 (M+H); MS (ESI) m/z 331.3 (M+2H); HRMS: calcd for C38H36N407 ■ HCI, 696.2351; found (ESI-), 659.24957; EXAMPLE 10 (6aR,7aS,8S, 11 aS)-2-(5-te/T-butyl-2-hydroxyphenyl)-5,8-bis(dimethylamino)- 9,11a,12-trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1- d][1,3ioxazo!e-10-carboxamide MS (ESI) m/z 631.4 (M+H); HRMS: calcd for QMHMNOOS ' HCI, 666.2456; found (ESI+), 631.27753; EXAMPLE 11 (6aR,7aS,8S,11aS)-2-[4-(ben2yloxy)phenylJ-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-^0X0-6,63,7,73,8,11,11a,13-octahydrotetraceno[2,1-dJ[1,3Joxazofe- 10-carboxamide MS '(ESI) m/z 665.2 (M+H); HRMS: calcd for CarH^^O,, • HCI, 700.2300; found (ESI+), 665.26096; EXAMPLE 12 ' (6aR,7aS)8SI11aS}-2-(2,4-dihydroxyphenyi)-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazo/e- 10-carboxamide MS (ESI) m/z 591.2 (M+H); HRMS: calcd for C30H30N4O9 • HCI, 626.1780; found (ESI-), 589.1927; EXAMPLE 13 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-(3-fluoro-4-methoxyphenyl)-9,11a,12- trihydroxy-11,13-^0X0-6,63,7,73,8,11,11a,13-octahydrotetracenof2,1-d][1,3]oxazole- 10-carboxamide MS (ESI) m/z 607.3 (M+H); MS (ESI) m/z 304 (M+2H); HRMS: calcd for C31H31FN408 • HCI, 642.1893; found (ESI-), 605.20519; EXAMPLE 14 (6aR,73S,8S,11 sS)-2-(1,3-benzodioxol-5-yl)-5,8-bis(dimethylamino)-9,11 a, 12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide MS (ESI) m/z 603.3 (M+H); MS (ESI) m/z302A (M+2H); HRMS: calcd for Ca^N^A): HCI, 638.1780; found (ESI+), 603.20953; EXAMPLE 15 (6aR,7aSl8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-(2,4,6- trimethoxyphenyl-e.eaJJa.S.11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide MS (ESI) m/z 649.2 (M+H); HRMS: calcd for C33H36N4ON,' HCI, 684.2198; found (ESI-), 647.23441; EXAMPLE 16 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-(2,4,5- triethoxyphenyl)-6,6a,7,7a,8,11,11a,13-octariydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide MS (ESI) m/z 691.3 (M+H); HRMS: cafcd for CasK^C^ • HCI, 726.2668; found (ESI+); 691.29817; EXAMPLE 17 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-thien- 3-^-6,63,7,73,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]o\azole-10-carboxamide MS (ESI) m/z 565.2 (M+H); MS (ESI) m/z 283.4 (M+2H); HRMS: calcd for C28H28N407S • HCI, 600.1445; found (ESI-), 563.15992; EXAMPLE 18 (6aR,7aS,8S,11 aS)-2-(1 -benzof uran-2-yl)-5,8-bis(dimethylamino)-9,11 a, 12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxarnide MS (ESI) m/z 599.3 (M+H); HRMS: calcd for C32H30N4OB ■ HCI, 634.1830; found (ESI-), 597.19811; EXAMPLE 19 (6aR7aS,8S>11aS)-5,8-bis(dimethylamino)-9I11a,12-trihydroxy-2-(1-rnethyl-1H- indol-2-yl)-11I13-dioxo-6,6al717a,l8,11,11a,13-octahydrotetraceno[2,'l-d]t1,3]oxazole- • 10-carboxamide MS(ESI)/n/z612.2(M+H); HRMS: calcd for C33H33N507 • HCI, 647.2147; found (ESI+), 612.24406; EXAMPLE 20 (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-2-(2-furyl)-9,11 a,12-trihydroxy-11,13- dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazo!e-10-carboxamide MS (ESI) m/z 549.3 (M+H); HRMS: calcd for C28H2BN408 • HCI, 584.1674; found (ESI-), 547.1822; EXAMPLE 21 {5-[(6aR,7aS,8S,11aS)-10-(aminocarbonyl)-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11 ,i3-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazol-2- yl]-2-furyl}methyl acetate MS (ESI) m/z 621.2 (M+H); HRMS: calcd for Ca^N^Co ■ HCI, 656.1885; found (ESI+), 621.21807; EXAMPLE 22 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(E)-2-(2-furyl)ethenyl]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide i MS (ESI) m/z 575.2 (M+H); MS (ESI) m/z 288.3 (M+2H); HRMS: calcd for C30H30N4O8 ■ HCI, 610.1830; found (ESI-), 573.1985; EXAMPLE 23 (6aR,7aS,8S,11aS)-2-(1-benzothien-3-yl)-5l8-bis(dimethylamino)-9,11a,12- trihydroxy-11,1 S-dioxo-e.eaJJa.B.11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide MS (ESI+) m/z 615.1 ((M+H)+); HRMS: calcd for C32H3DN407S • HCl, 650.1602; found (ESI+), 615.19036; EXAMPLE 24 (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy-11,13-dioxo-2-(1,3- thiazol-2-yl)-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide MS (ESI) m/z 566.4 (M+H); MS (ESI) m/z 283.6 (M+2H); HRMS: calcd for C27H27N507S • HCl, 601.1398; found (ESI+), 566.16973; EXAMPLE 25 (6aR,7aS,8S, 11 aS)-5,8-bis(dimethylamino)-9,11 a, 12-trihydroxy-11,13-dioxo-2-[( E)-2- phenylethenyl]-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxaroide v MS (ESI) m/z 585.4 (M+H); MS (ESI) m/z 293.3 (M+2H); HRMS: calcd for CaaHaa^Or • HCI, 620.2038; found (ESI+), 585.2329; EXAMPLE 26 (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy-2-[(E)-2-(4- methoxyphenyl)ethenyl]-11,13-dioxo-6,6a,7,7a,8,111-\ 1 a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide MS (ESI) m/z 615.3 (M+H); MS (ESI) m/z 308.3 (M+2H); HRMS: calcd for C33H34N408 • HCI, 650.2143; found (ESI+), 615.24413; EXAMPLE 27 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihyciroxy-2-[(E)-2-(3- methoxyphenyl)ethenyl]-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide MS (ESI) m/z 615.4 (M+H); MS (ESI) m/z 308.3 (M+2H); HRMS: calcd for CssH^Oe' HCI, 650.2143; found (ESI+), 615.24419; EXAMPLE 28 (6aR,7aSI8SI11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-2-[(E)-2-(2- methoxyphenyl)ethenyl]-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 - d][1,3]oxazole-10-carboxamide MS (ESI) m/z 615.3 (M+H); MS (ESI) m/z 308.3 (M+2H); HRMS: calcd for CaaH^Oj, • HCI, 650.2143; found (ESI+), 615.24408; ;EXAMPLE 29 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(E)-2-(4-fluorophenyl)ethenyl]- 9,11a,12-trihydroxy-11 ,13^10X0-6,63,7,73,8,11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide MS (ESI) m/z 603.3 (M+H); MS (ESI) m/z 302.3 (M+2H); HRMS: calcd for C32H31FN407 • HCI, 638.1944; found (ESI+), 603.22476; EXAMPLE 30 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(E)-2-(2-fluorophenyl)etrienyl]- 9,11a,12-trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide MS (ESI) m/z 603.2 (M+H); MS (ESI) m/z 302.3 (M+2H); HRMS: calcd for C32H3iFN407 • HCI, 638.1944;,found (ESI+), 603.22469; EXAMPLE 31 (6aR,7aS,8S,11aS)-2-(4-tert-butylphenyl)-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-610X0-6,63,7,78,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide MS(ESI)m/z615.3(M+H); MS (ESI) m/z 308.3 (M+2H); HRMS: calcd for C34H38N407 ■ HCI, 650.2507; found (ESI+), 615.28057; EXAMPLE 32 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[4-(hexyloxy)phenyl]-9,11aI12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide MS (ESI) m/z 659.4 (M+H); MS (ESI) m/z 330.4 (M+2H); HRMS: calcd for C36H42N40B • HCI, 694.2769; found (ESI+), 659.30693; EXAMPLE 33 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- pyl]din-4-yl-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxamide EXAMPLE 34 (6aRI7aS,8S,11aS)-5I8-bis(dimethylamino)-9,11al12-trihydroxy-11,13-ciioxo-2- pyl]din-3-yl-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,i-d][1,3]oxazole-10- carboxamide MS (ESI) m/z 560.3 (M+H); MS (ESI) m/z280.7 (M+2H); HRMS: calcdfor C^^NgO/" HCI, 595.1834; found (ESI+), 560.21353; EXAMPLE35 (6aR,7aS,8S,11aS)-2-(chloromethyl)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide MS (ESI) m/z 531.2 (M+H); MS (ESI) m/z 266.3 (M+2H); EXAMPLE 36 (6aR7aS,8S>11aS)-5I8-bis(dimethylamino)-2-[(dimethylamino)methyl]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide MS (ESI) m/z 540.4 (M+H); MS (ESI) m/z270.7 (M+2H); HRMS: calcd for C27H33Ns07 • HCI, 575.2147; found (ESI+), 540.24506; EXAMPLE 37 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- (pyrrolidin-1-ylmethyl)-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole- . 10-carboxamide MS (ESI) m/z 566.4 (M+H); MS (ESI) m/z283.9 (M+2H); HRMS: calcd for C29H35N507' HCI, 601.2303; found (ESI+), 566.26066; Example of Procedure B EXAMPLE 38 (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,l' 1 a,12-trihydroxy-11,13-dioxo-2- [(propylamino)methyl)-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide 9-aminominocycline sulfate salt (1.0 g, 1.50 mmol) is dissolved in DMF (50 mL) and treated with a solution of 2-chIoro-1,1,1 -trimethoxyethane (0.463 g, 3.00 mmol, 2 equivalents). The reaction is stirred at room temperature until mass spectrometry shows conversion to the chloromethylbenzoxazole derivative. The solution is then treated with ^propylamine (10 mL, excess) and stirred until mass spectrometry shows conversion to the n-propylaminomethyl benzoxazole. The mixture is concentrated under reduced pressure to remove excess n-propylamine, and then poured slowly into ether (1 L) and HCI/ether is added to precipate the salt. The solid is rinsed with fresh ether and dried under vacuum. The crude solid is dissolved in water (100 mL) giving a solution at pH 2. The pH is raised successively by 0.5 units with aqueous ammonia, and extracted with dichloromethane. The fractions extracted at pH 4-4.5 are combined, dried (Na2S04), filtered and concentrated nearly to dryness. A small volume of methanol is added and the solution is treated with 1M HCI in ether. The precipitated solid is collected by filtration, washed with fresh ether and dried under vacuum to yield 0.067 g of the product as its HCI salt. Selected 1H NMR signals: 5 0.94 (t, 3H), 1.73 (m, 2H), 4.31 (s, 1H), 4.65 (s, 2H), 7.78 (s, 1H), 9.15 (s, 1H), 9.67 (s, 1H). The compounds of this invention listed below in Examples 39 to 41 are prepared substantially following the method described in detail hereinabove in Example 38 using procedure B. (prepared from Procedure B) EXAMPLE 39 (6aR,7aS,8S,11aS)-2-[(butylamino)methyl]-5,8-bis(dimethyIamino)-9,11a,12- trihydroxy-11,13^10X0-6,63,7,73,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide MS (ESI) m/z568.3 (M+H); MS (ESI) m/z 284.8 (M+2H); MS (ESI) m/z 305.2 (M+ACN+2H); HRMS: caicd for C29H37N507 • HCl, 603.2460; found (ESI+), 568.27616; (Procedure B) EXAMPLE 40 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- [(propylamino)methyl]-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazo!e- 10-carboxamide MS (ESI) m/z554.3 (M+H); MS (ESI) m/z277.7 (M+2H); HRMS: calcd for CzaHasNsOr ■ HCl, 589.2303; found (ESI+), 554.2604; (Procedure B) EXAMPLE 41 (6aR7aS3S,11aS)-2^(fe/t-butylamino)methyl]-5,8-bis(dimethylarriirio)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide 9-aminominocycline sulfate salt (1.0 g, 1.50 mmol) is dissolved DMF (20 ml_) and treated with a solution of 2-chlorotrimethoxyethane (0.35 g, 2.2 mmol, 1.46 equivalents). The reaction is stirred at room temperature until mass spectrometry showed conversion to the chloromethylbenzoxazole derivative. The solution is then treated with f-butylamine (7.3 ml_, excess) and stirred until mass spectrometry showed conversion to the f-butylaminomethyl benzoxazole. The mixture is concentrated under reduced pressure to remove excess f-butylamine, and then poured slowly into ether (1 L) and HCI/ether is added to precipate the salt. The solid is rinsed with fresh ether and dried under vacuum. The crude solid is dissolved in water (100 mL) giving a solution at pH 2. The pH is raised successively by 0.5 units with aqueous ammonia, and extracted with dichloromethahe. The fractions extracted at pH 4-4.5 are combined, dried (Na2S04), filtered and concentrated nearly to dryness. A small volume of methanol is added and the solution is treated with 1M HCI in ether. The precipitated solid is collected by filtration, washed with fresh ether and dried under vacuum to give the product as its HCI salt. MS (ESI+) m/z568.4 ((M+H)-i-); MS (ES1+) m/z 284.9 ((M+2H)2+); MS (ESI+) m/z 146.3 ((M'+H)+); HRMS: calcd for C^r^NgO?' HCI, 603.2460; found (ESI-), 566.26087; Example of Procedure C EXAMPLE 42 (6aR,7aS,8S, 11 aS)-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy-11,13-dioxo-2- thioxo-2,3,6,6a,7,7a,8,11,11 a,13-decahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxamide To a solution of 9-amino-mino disulfate (0.668 g, 1 mmol) in DMSO (30 mL) is added 2 equivalents of 1,1-thiocarbonyldiimidazole. The reaction is then stirred at room temperature for 2 to 12 hr (followed by MS(ES)). The mixture then triturated with diethyl ether and the solid collected. Material is used in the next step without further purification. MS (ESI) m/z 515.2 (M+H); HRMS: calcd for C^r^N^S • H2S04) 612.1196; found (ESI+), 515.15934; The compounds of this invention listed below in Examples 43 to 44 are prepared substantially following the method described in detail hereinabove in Example 42 using procedure C. Example of procedure C (Procedure C) EXAMPLE 43 benzyl {[(6aR,7aS,8S,11aS)-10-(aminocarbonyl)-5,8-bis(dimethylamino)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazol-2- yl]thio}acetate To a solution of (6aR,7aS,8S,11aS)-5,8-bis(dimethylarriino)-9,11al12-trihydroxy- 11,13-dioxo-2-thioxo-2,3,6,6a,7,7a,8,11,11 a,13-decahydrotetraceno[2,1 - d][1,3]oxazole-10-carboxamide (Example 42) in N,N-dimethylformamide (DMF) is added 2 equivalents of diisopropylethylamine, after stirring for 5 min. 1.2 equivalent of benzyl-2-bromoacetate is added. The reaction mixture is stirred for 1 hr and mixture triturated with diethyl ether and solid is collected. It is purified by extraction. MS (ESI) m/z 663.2 (M+H); MS (ESI) m/z 332.1 (M+2H); HRMS: calcd for CaaH^OgS ■ HCI, 698.1813; found (ESI+), 663.2115; EXAMPLE 44 (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(4-fluorobenzyl)thio]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide The compound of the example is prepared using procedure D in Example 43 using 4- fluorobenzylbromide. MS (ESI) m/z 622.9 (M+H); HRMS: calcd for C3iH31FN407S • HCI, 658.1664; found (ESI+), 623.19689; Example of Procedure D (Compound 1 to 4 to 6) Example 45 [4S-(4a,4aa,5aa, 12aa)]-4,7-Bis(dimethylamino)-9-[2-(1,1 - dimethylethylamino)acetylamino]-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a- tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide. (mono HCI); (free base) 9-aminominocycIine sulfate salt (1.0 g, 1.50 mmol) is dissolved DMF (20 mL) and treated with a solution of 2-chlorotrimethoxyethane (0.35 g, 2.2 mmol, 1.47 equivalents). The reaction is stirred at room temperature until mass spectrometry showed conversion to the chloromethylbenzoxazole derivative. The solution is then treated with f-butylamine (7.3 mL, excess) and stirred until mass spectrometry showed conversion to the f-butylaminomethyl benzoxazole. The mixture is concentrated under reduced pressure to remove excess f-butylamine, and then poured slowly into ether (1 L) and HCI/ether is added to precipate the salt. The solid is rinsed with fresh ether and dried under vacuum. The crude solid is dissolved in water (100 mL) giving a solution at pH 2. The pH is raised successively by 0.5 units with aqueous ammonia, and extracted with dichloromethane. The fractions extracted at pH 4-4.5 are combined, dried (Na2S04), filtered and concentrated nearly to dryness. A small volume of methanol is added and the solution is treated with 1M HCI in ether. The precipitated solid is collected by filtration, washed with fresh ether and dried under vacuum to give the product as its HCI salt. Product from example 41 is treated with aqueous acid for one hour to 24 hour to give mono HCL salt of example 45 MS (ESI+)m/z 586.4 ((M+H)+; The following examples are prepared using similar method described in procedure D. Example 46 [4S-(4a,4aa,5aa,12aa)]-4,7-Bis(dimethylamino)-9-[(dimethyamino)acetylamino]- 1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2- naphthacenecarboxamide. MS (FAB) m/z 558 ((M+H)+; Example 47 [4S-(4a,4acc,5act, 12aa)]-4,7-Bis(dimethylamino)-9-[[(n-butylamino)acetyl]amino]- 1,4,48,5,53,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11 -dioxo-2- naphthacenecarboxamide. MS (FAB) m/z 586 ((M+H)+; 1 Example 48 [4S-(4a,4aal5aa,12aa)]-4,7-Bis(dimethylamino)-9-[[(propylamino)acetyI]amino]- 1,4,4a,5,5a,6,11,12a-octahydro-3,10(12,12a-tetrahydroxy-1,11-dioxo-2- naphthacenecarboxamide MS (FAB) m/z 572 ((M+H)+; Example 49 [4S-(4a,4aa,5aa,12aa)]-4,7-Bis(dimethylamino)-9-[(chloroacetyl)amino]- 1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11 -dioxo-2- naphthacenecarboxamide MS (FAB) m/z 549 ((M+H)+; WE CLAIM: 1. A compound of Formula (I); wherein: X is selected from hydrogen, amino, NR11R12, alkyl of 1 to 12 carbon atoms optionally substituted , aryl of 6,10 or 14 carbon atoms optionally substituted, vinyl optionally . substituted, alkynyl of 2 to 12 carbon atoms optionally substituted and halogen; A" is a moiety selected from the group: R11 and R12 are each independently H or alkyl of 1 to 12 carbon atoms or R11 and R12 when optionally taken together with the nitrogen atom to which each is attached form a 3 to 7 membered saturated hydrocarbon ring; Y is selected from hydrogen, alkyl of 1 to 12 carbon atoms optionally substituted, aryl of 6,10 or 14 carbon atoms optionally substituted, alkenyl of 2 to 12 carbon atoms optionally substituted, vinyl, alkynyl of 2 to 12 carbon atoms optionally substituted and halogen; R is selected from alkyl of 1 to 12 carbon atoms optionally substituted, alkenyl of 2 to 6 carbon atoms optionally substituted, alkynyl of 2 to 12 carbon atoms optionally substituted, -CH2NR1R2, aryl of 6,10 or 14 carbon atoms optionally substituted, aralkyl of 7 to 16 carbon atoms optionally substituted, aroyl of 7 to 13 carbon atoms optionally substituted, SR3, heteroaryl of 5 or 6 ring atoms optionally substituted, containing 1 to 4 heteroatoms which may be the same or different, independently selected from nitrogen, oxygen and sulfur, and heteroarylcarbonyl of 5 or 6 ring atoms optionally substituted containing 1 to 4 heteroatoms which may be the same or different, independently selected from nitrogen, oxygen and sulfur; R1 and Rz are each independently H or alkyl of 1 to 12 carbon atoms or R1 and R2 when optionally taken together with the nitrogen atom to which each is attached form a 3 to 7 membered saturated hydrocarbon ring; R3 is alkyl of 1 to 12 carbon atoms optionally substituted, -CH2-aryl optionally substituted, aralkyl of 7 to 16 carbon atoms optionally substituted, aroyl, -CH2(CO)OCH2aryI optionally substituted, -CH2-alkenyl of 2 to 12 carbon atoms optionally substituted, and -CH2-alkynyl of 2 to 12 carbon atoms optionally substituted; with the proviso that when X is NR1R2 and R1 is hydrogen, then R2 is methyl, ethyl, n- propyl, n-butyl, 1-methylethyl, 1 -methylpropyl, 2-methylpropyi or 1,1-dimethylethyl; and that when R1 is methyl or ethyl then R2 is methyl, ethyl, n-propyl, 1 -rnethylethyl, n-propyl, 1-rnethy(propyi, or 2-methylpropyl; or a tautomer or a pharmaceutically acceptable salt thereof. 2. A compound as claimed in claim 1 wherein R is phenyl optionally substituted with 1 to 3 substituents or a pharmaceutically acceptable salt thereof. 3. A compound as claimed in claim 1 wherein R of Formula (I) is selected from the group alkyl of 1 to 6 carbon atoms, alkenyf of 2 to 6 carbon atoms, and aikyl-heterocyclyl or a pharmaceutically acceptable salt thereof. 4. A compound as claimed in claim 3 wherein alkyl-heterocyclyl is selected from moieties of the group or a pharmaceutically acceptable salt thereof. 5. A compound as claimed in claim 2 wherein R is selected from moieties of the group or a pharmaceutically acceptable salt thereof. 6. A compound as claimed in claim 1 wherein R is heteroaryl or a pharmaceutically acceptable salt thereof. 7. A compound as claimed in claim 6 wherein R is selected from moieties selected from the group or a pharmaceutically acceptable saltthereof. 8. A compound as claimed in claim 1 wherein R is alkyl of 1 to 6 carbon atoms optionally substituted, alkenyl of 2 to 6 carbon atoms optionally substituted, NH(cycloaIkyl of 5 to 6 carbon atoms), NH(alkyl of 1 to 6 carbon atoms) and NH(alkyl of 1 to 6 carbon atoms)-aryl optionally substituted, or a pharmaceutically acceptable salt thereof. 9. A compound as claimed in claim 1 wherein R is selected from moieties or a pharmaceutically acceptable salt thereof. 10. A compound as claimed in claim 1 wherein R is S-alkyl of 1 to 12 carbon atoms, S-CH2-aryl optionally substituted and S-CH2(CO)OCH2aryl optionally substituted or a pharmaceutically acceptable salt thereof. 11. A compound as claimed in claim 10 wherein R is selected from moieties of the group or a pharmaceutically acceptable salt thereof. 12. A compound as claimed in any one of claims 1 to 11 wherein Y is H. 13. A compound as claimed in any one of claims 1 to 12 wherein X is -NMe2. 14. A compound as claimed in claim 1 selected from the group: (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-2-(2,2-diphenylvinyl-9,11a,12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxamide, (7aS,8S,11aS)-8-(dimethyIamino)-9,11a,13-trihydroxy-2-(2-methyl-1-propenyl)- 11,12-dioxo-7,7a,8,11,11a,12-hexahydronaphthaceno[2,1-d][1,3]oxazole-10- carboxamide, (6aR,7aS,8S,11 aS)-2-tert-buty[-5,8-bis{dimethylamino)-9,11 a,12-trihydroxy-11,13- dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(E)-2-(2-furyl)ethenyl]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-5l8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-[(E)-2- phenylethenyl]-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazoIe-10- carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9.11a,12-trihydroxy-2-[(E)-2-(4- methoxyphenyl)ethenyl-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy-2-[(E)-2-(3- methoxyphenyl)ethenyl-11,13-dioxo-6,6a,7a,8, 11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-2-[(E)-2-(2- methoxyphenyl)ethenyI]-11,13-dioxo-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(E)-2-(4-fluorophenyl)ethenyl- 9,11 a,12-trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[(E)-2-(2-fluorophenyl)ethenyl]- 9,11 a,12-trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1- d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-2-(chloromethyl)-5,8-bis(dimethylamino)-9,11aI12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazoie-10- carboxamide, (6aR,7aS,8S, 11 aS)-5,8-bis(dimethylamino)-2-[(dimethylamino)methyl]-3,11a, 12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11 a, 12-trihydroxy-11,13-dioxo-2- (pyrrolidin-1-ylmethyl)-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- [(propylaminoJmethylJ-S.eaJ^a, 8,11,11 a, 13-octahydrotetraceno[2,1-d][1,3Joxazole- 10-carboxamide, (6aR,7aS,8Sl11aS)-2-[(butylamino)methyl]-5l8-bis(dimethylamino)-9,11a,12- trihydroxy-11l13-dioxo-6,6a,7,7a,8J11I11a>13-octahydrotetraceno[2,1-d]_[1,3Joxazole- . 10-carboxamide, (6aR,7aS,8S,11aS)-5l8-bis(dimethylamino)-9l11a,12-trihydroxy-11,13-dioxc-2- [(propylamino)methyl-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazoIe- 10-carboxamide and (6aR,7aS,8S,11aS)-2-[(terf-butylamino)methyl-5,8-bis(dimethylamino)-9,1ia,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazoIe- •10-carboxamide; or a pharmaceutically acceptable salt thereof. 15. A compound as claimed in claim 1 selected from the group: (7aS,8S,11 aS)-8-(dimethylamino)-2-[4-(dimethylamino)phenyl]-9,11 a,13-trihydroxy- 11,12-dioxo-7,7a,8,11,11 a,12-hexahydronaphthaceno[2,1 -d][1,3]oxazole-10- carboxamide, (6aR,7aS,8S,11 aS)-2-tert-butyl-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy-11,13- dioxo6,6a,7,7a,8l11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11 aSJ-S.S-bisCdirnethylamino)^^ 1 a,12-trihydroxy-2-(4-methylphenyl)- 11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide, (7aS,85,11 aS)-5,8-bis(dimethy lamino)-2-(3-fluorophenylj-9,11 a, 13-trihydroxy-11,12- dioxo-7,7a,8,11,11a,12-hexahydrotetraceno[2,1-d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11 aS)-2-(4-cyanophenyl)-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy- 11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-2-[4-(dimethylamino)phenyl]-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazo!e- 10-carboxamide, (6aR,7aS,8S,11aS)-2-(5-ferf-butyl-2-hydroxyphenyl)-5,8-bis(dimethyiamino)- 9,11 a,12-trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 - d][1,3]oxazole-10-carboxamide, (eaR^aS.SS.HaSJ^-^benzyloxyJphenyl]-S.S-bisCdimethylaminoJ-g.lla,^- trihydroxy-T1,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aRJaS,8SJ1aS)-2-{2,4-dihydr6xyphenyl)-5,8-bis(dirnethylamino)-9,11a,12- trihydroxy-11,13^0X0-6,63,7,73,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide, (6aR)7aS,8S,11aS)-5)8-bis(dimethylamino)-2-(3-fluoro-4-methoxyphenyl)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6a R,7aS,8S,11 aS)-2-(1,3-benzodioxol-5-yl)-5,8-bis(dimethylamino)-9,11 a,12- trihydroxy-11,13-dioxo-6,63,7)7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimethyfamino)-9,11a,12-trihydroxy-11,13-dioxo-2- (2,4,6-trimethoxypfienyl)-6,63,7,73,8,11,11 a, 13-oct3hydrotetraceno[2,1 - d][1,3]oxazole-10-carboxamide,.... ._....- (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-(2,4,5- triethoxyphenyl)-6,6a,7,73,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazoie-10- carboxamide, (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-2-(1-methyl-1H- indoi-2-yl)-11,13^0X0-6,63,7,73,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS,8S,11 aS)-2-(4-ferf-butyiphenyl)-5,8-bis(dimethyl3mino)-9J113,12- trihydroxy-11,13-dToxo-6,63,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazoIe- 10-carboxamide and (6aR,7aS,8S,11 aS)-5,8-bis(dimethylamino)-2-[4-(hexyloxy)phenyl-9,11 a, 12- trihydroxy-11,13-^0X0-6,63,7,73,8,11,113,13-oct3hydrotetraceno[2,1-d][1,3]oxazole- 10-csrboxamide or a pharmaceutically acceptable salt thereof. 16. A compound as claimed in claim 1 selected from the group: (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11I13-dioxo-2-thien- 3-yl-6,6a,7,7a,8,11,11 a, 13-octahydrotetraceno[2,1 -d][1,3]oxazole-10-carboxamide, (6aR,7aS,8S,11aS)-2-(1-benzofuran-2-yl)-5,8-bis(dimethy[amino)-9,11a,12- trihydroxy-11,13-dioxo-6,6a,7,7a, 8,11,11 a, 13-octahydrotetraceno[2,1 -d][ 1,3]oxazoIe- 10-carboxamide, (6aR,7aS,8S,11aS)-5,8-bis(dimetriylamino)-2-(2-furyl)-9,11 a,12-trihydroxy-11,13- dioxo-6,6a,7,7ar8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10-carboxamide, {5-[(6aR,7aS,8S,11aS)-10-(aminocarbonyl)-5,8-bis(dimethyl2rriino)-9,11 a, 12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazol-2- yl]-2-furyl}methyl acetate, (6aR,7aS,8S,11 aS)-2-(1 -benzothien-3-yl)-5,8-bis(dimethylamino)-9,11 a, 12- trihydroxy-11,13-dioxo-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole- 10-carboxamide, (6aR,7aS>8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2-(1,3- thiazol-2-yl)-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1-d][1,3]oxazole-10- carboxamide, (6aR,7aS,8S, 11 aS)-5,8-bis(dimethylamino)-9,11 a,12-trihydroxy-11,13-dioxo-2- pyl]din-4-yl-6,6a,7,7a,8,11,11a,13-octahydrotetraceno[2,1.-d][1,3]oxazo!e-10- carboxamide and (6aR,7aS,8S,11aS)-5,8-bis(dimethylamino)-9,11a,12-trihydroxy-11,13-dioxo-2- pyl]din-3-yl-6,6a,7,7a,8,11,11 a,13-octahydrotetraceno[2,1 -d][1,3]oxazole-10- carboxamide or a pharmaceutically acceptable salt thereof. 17. A pharmaceutical composition comprising a compound as claimed in any one of claims 1 to 16 or a pharmaceutically acceptable salt thereof in association with a pharmaceutically acceptable carrier. 18. A process for preparing a compound of formula I as claimed in claim 1 which comprises a). reacting 7-(substituted)-8-(substituted)-9-amino-6-demethyI-6- deoxytetracyclin e of the formula or a pharmaceutically acceptable salt thereof with 2-chlorotrimethoxyethane in an aprotic solvent to afford a chloro compound of the formula wherein the variables are as defined in claim 1 ; or b. reacting a chloro compound of formula wherein the variables are as defined in claim 1; with an amine R1R2NH to form a substituted amine of the formula or c) converting a basic compound of formula I as defined in claim 1 to a pharmaceutically acceptable salt thereof or vice versa. (54) Title: OXAZOLE DERlVATIVES OFTETRACYCLINES (57) Abstract: This invention provides compounds of (he formula: wherein A". X and Y are defined in (he specification. These compounds are useful as antibacterial agents.