Patent ID: 6143885
Filing Date: 2000-11-07
Classification: C07F,Y02P

Abstract:
A process for synthesizing a componud of formula 5: ##STR18## wherein: R.sup.a is:(1) hydrogen,(2) C.sub.1-4 alkyl or(3) a hydroxy protecting group; andR.sup.b and R.sup.c are independently:tri-C.sub.1-6 alkyl silyl, phenyl di-C.sub.1-6 alkyl silyl, and diphenyl mono C.sub.1-6 alkyl silyl selected from tert-butyl-dimethylsilyl, hexyldimethylsilyl and isopropyl dimethylsilyl; straight and branched lower alkyl having from 1 to 10 carbon atoms; alkenyl or alkynyl, having from 2 to 10 carbon atoms; cycloalkyl having from 3 to 6 carbon atoms; cycloalkylalkyl wherein the cycloalkyl moiety comprises 3 to 6 carbon atoms and the alkyl moiety comprises 1 to 10 carbon atoms; alkylcycloalkyl wherein the alkyl moiety comprises 1 to 6 carbon atoms and the cycloalkyl moiety comprises 3 to 6 carbon atoms; aryl, selected from phenyl and naphthyl; aralkyl selected from benzyl and phenethyl; heterocyclyl (saturated and unsaturated) comprising structures having from 5 to 10 ring atoms, wherein one or more of the heteroatoms is oxygen, nitrogen, or sulfur, selected from thiophene, imidazolyl, tetrazolyl, and furyl; heterocycloalkyl which comprises the immediately preceding heterocyclyl moieties and the alkyl moiety comprises from 1-10 carbon atoms; substituted species of the above named radicals wherein the substituents are selected from the group consisting of amino, hydroxyl, cyano, carboxyl, nitro, chloro, bromo, or fluoro; perhaloloweralkyl selected from trifluoromethyl; guanidino; amidino; sulfamoyl; N-substituted sulfamoyl, amidino, and guanidino wherein the N-substituent is lower alkyl having from 1 to 6 carbon atoms or aryl having 6-10 carbon atoms; COR or CO.sub.2 R, wherein R is lower alkyl having from 1 to 6 carbon atoms or aryl having 6-10 carbon atoms; wherein lower alkyl is C.sub.1-6 alkyl and wherein R.sup.b and R.sup.c may be the same or different, but R.sup.b must be removable in the presence of R.sup.c ; andR.sup.1 is an alkylsilyl protecting group;comprising: reacting the ketoester of formula 4; ##STR19## wherein R.sup.a, R.sup.b, R.sup.c and R.sup.1 are described above; with an acid and a first catalyst selected from Pd/C, Pd(OH).sub.2 /C and (Ra)Ni at a temperature of about 0.degree. C. to about 50.degree. C. with about 0-500 psi H.sub.2, to give a compound of formula 5.