Patent ID: 7026144

Claim:
A process of separating a single stereoisomer from a racemic mixture of eight stereoisomers of a compound of the formula III: wherein R 1 represents an isopropanol group, an isopropyl group or an isopropylene group, including the steps of: (1) contact the racemic mixture in a suitable organic solvent with an esterifying agent and a stereospecific enzyme which stereoselectively esterfies the —OH group of the single stereoisomer, for a time sufficient to convert the single stereoisomer to a compound of the formula IV without the reaction proceeding to the esterification of any of the other of the eight stereoisomers of the racemic mixture: wherein R 1 is as defined above and R 4 is an alkyl or an aryl group, to give a first reaction product including the compound of the formula IV, the organic solvent, the unconverted stereoisomers of the compound of the formula III, excess esterfying agent and by-products of the reaction; and (2) separating the compound of the formula IV from the first reaction product.