Patent ID: 6399770
Filing Date: 2002-06-04
Classification: C07D,Y02P

Abstract:
A process for preparing a &bgr;-hydroxyester of the formula (2) comprising reducing a 3-keto cepham compound represented by the formula (1) or a 3-hydroxycephem compound represented by the formula (1â€²) which is the keto-enol isomer of the 3-keto cepham compound wherein R1 is hydrogen atom, halogen atom, amino group, protected amino group or a group â€”N&boxH;CHâ€”Ar (in which Ar is phenyl group optionally having a substituent selected from the group consisting of lower alkoxyl, nitro and hydroxyl), R2 is lower alkyl group optionally having a hydroxyl group or protected hydroxyl group as a substituent, hydrogen atom, halogen atom, lower alkoxy group, RC(O)â€”, where R is straight-chain or branched lower alkyl, hydroxyl group or protected hydroxyl group, and R3 is hydrogen atom or carboxylic acid-protecting group, in the presence of a salt selected from the group consisting of ammonium borohydride and tetraalkylammonium borohydride.