Patent ID: 6262295
Filing Date: 2001-07-17
Classification: C07B,C07C,C07D,C12P

Abstract:
A Process for the preparation of a racemic or optically active of the formula ##STR20##in which the group R.sup.1 is an unsubstituted or a halogen substituted C.sub.1-4 -alkyl, a C.sub.1-4 -alkoxy, an aryl, arylalkyl, arylalkyloxy or an aryloxy, characterized in that in the first stage a cyclopentene-4-carboxylic acid of the formula ##STR21##in the form of the racemate or one of its optically active isomers, is acylated with a carbonyl halide of the general formula ##STR22##in which the group R.sup.1 is an unsubstituted or a halogen substituted C.sub.1-4 -alkyl, a C.sub.1-4 -alkoxy, an aryl, or an aryloxy and in which X is a halogen, to give a racemic or optically active cyclopentene-4-carboxylic acid derivative of the general formula ##STR23##and the latter is reduced in the second stage to give the required product of the formula XIII by reacting the racemic or optically active cyclopentene-4-carboxylic acid derivative of the general formula XV with either (i) an alkali metal aluminum hydride, (ii) a borane/di-C.sub.1-4 -alkyl sulfide complex, or (iii) a borane/tetrahydrofuran complex, in the presence of a solvent wherein the solvent is an anhydrous ether.