Patent ID: 6593489
Filing Date: 2003-07-15
Classification: C07B,C07C,C07D,Y02P

Abstract:
A method of preparation of an isomerically pure compound having a structure as shown in (4a)-(4d): or the opposite enantiomers thereof, wherein X is selected from the group consisting of alkyl, H, and a salt-forming cation, andR2 is H or a protecting group; R3 is H or alkyl; and R4 is selected from the group consisting of H, alkoxy, alkyl, aryl, and aralkyl; or, in the case of formula (1A), R2 and R4 are linked to form an oxazolidinone ring; and wherein said method comprises the use, in stereoselective hydrogenation, of a substituted cyclopentene compound, in substantially enantiopure form, having the relative stereochemistry according to formula (1A) or (1B) including the opposite enantiomers, whereinR1 is either COOX, wherein X is selected from the group consisting of alkyl, H, and a salt-forming cation, or CH2OH, wherein the hydroxyl group is optionally protected; R2 is H or a protecting group; R3 is H or alkyl; and R4 is selected from the group consisting of H, alkoxy, alkyl, aryl, and aralkyl; or, in the case of formula (1A), R2 and R4 are linked to form an oxazolidinone ring; such that said isomerically pure compound having a structure as shown in (4a)-(4d) is produced by stereoselective hydrogenation of said substituted cyclopentene compound.