Patent ID: 6417389
Filing Date: 2002-07-09
Classification: C07C

Abstract:
A process for the preparation of a compound of formulae whereinA is C1-C7alkyl, C1-C7alkoxy, C1-C4alkanoyl, C1-C4alkanoyloxy, cyanogen, halogen, hydroxy, carboxy, C1-C4alkoxycarbonyl, C1-C7alkylenedioxy, amino, C1-C4alkylamino, di(C1-C7alkyl)amino, C1-C4alkanoylamino, carbamoyl, C1-C4alkylcarbamoyl, di(C1-C7alkyl)carbamoyl, C1-C4alkanesulfonylamino, arenesulfonylamino, sulfo, sulfamoyl, C1-C4alkylsulfamoyl, di(C1-C7alkyl)sulfamoyl, halogen-C1-C7alkyl, hydroxy-C1-C7alkyl or amino-C1-C7alkyl, m is an integer from 0 to 5 and R is C1-C20alkyl, C3-C12cycloalkyl, tetrahydrofuryl, pyrrolidinyl, piperazinyl, tetrahydrothienyl, phenyl, naphthyl, furyl, thienyl, pyrrolyl, pyridyl, pyrimidinyl or benzyl, each of which is unsubstituted or substituted by one or more than one substituent selected from the group consisting of C1-C6alkyl, C1-C6alkoxy, C1-C6haloalkyl, phenyl, naphthyl, carboxy, C1-C4alkoxycarbonyl, C1-C4alkanoyl, â€”SO3âˆ’, ammonium and halogen, which comprises enantioselectively hydrogenating an &agr;,&ggr;-diketo ester of formula wherein A, m and R have the cited meanings, or the tautomer thereof, with platinum as catalyst in the presence of a cinchona alkaloid as chiral modifier, and hydrogenating one of the obtainable compounds of formulae â€ƒhaving the desired configuration with palladium as catalyst.