Travoprost method of preparation

摘要

The present invention is a process for preparing travoprost of formula (I), wherein the compound of formula (II) is stereoselectively reduced and the resulting compound of formula (III) is crystallized if desired, Reduction of the lactone group of the compound of (III), removal of the p-phenylbenzoyl protecting group of the compound of formula (IV) thus obtained and the triol of formula (V) If so, it relates to a method of crystallization followed by conversion to an acid of formula (VI) by Wittig reaction and esterification.