Preparation of piperidinylcyclopentylheptenoic acid derivatives

摘要

A process is described for the preparation of a compound of formula (2) <IMAGE> (2) (wherein R is a C1-6 alkyl or a C7-20 aralkyl group) and the salts thereof, which comprises reducing a compound of formula (3) <IMAGE> (3) (or a salt thereof), using a reducing system comprising borohydride ions and metal ions selected from lanthanide ions, alkaline earth metal ions or yttrium ions in solution. The reduction system may be provided by a borohydride (e.g. NaBH4) and a metal salt (e.g. CeCl3). The ester (2) may then if desired be hydrolyzed to give the parent acid.