Abstract: Methods of separating stereoisomers of a racemic mixtures of a compound employ porcine pancreatic lipase which selectively transesterfies one enantiomer of an ester function which is proximate to a chiral isomeric site are presented. The compound is a reactive ester of the formula: ##STR1## The method comprises obtaining a racemic mixture of the reactive ester, reacting the reactive ester with a poly(ethylene glycol) of average molecular weight of about 100 to about 10,000 Daltons and the enzyme. The reactive ester, the poly(ethylene glycol) and the enzyme are reacted in a medium in proportions other conditions effective to form a chiral site proximate poly(ethylene glycol) ester. The chiral site approximate poly(ethylene glycol) ester is then separated from the reaction medium, the reactive ester, the poly(ethylene glycol) and the enzyme.

Abstract: Optically active polymers are of the formula ##STR1## wherein R and R.sup.1 are different from each other and are selected from the group consisting of (C.sub.1 -C.sub.20)alkyl, (C.sub.2 -C.sub.20)alkenyl, (C.sub.2 -C.sub.20)alkynyl, (C.sub.3 -C.sub.22) cycloalkyl and (C.sub.6 -C.sub.22)aryl, the alkyl, alkenyl and alkynyl further including an atom selected from the group consisting of N, O and S in the chain, the alkyl, alkenyl and alkynyl further including a substituent selected from the group consisting of (C.sub.1 -C.sub.4)alkyl and halogen atoms, the cycloalkyl and aryl further including an atom selected from the group consisting of N, O and S in the ring, and the cycloalkyl and aryl further including a substituent selected from the group consisting of (C.sub.1 -C.sub.10)alkoxy, aryloxy, halogen atoms, NO.sub.2 and NHCOR.sup.4 wherein R.sup.4 is selected from the group consisting of (C.sub.1 -C.sub.6)alkyl, (C.sub.2 -C.sub.6)alkenyl, (C.sub.2 -C.sub.6)alkynyl and (C.sub.6 -C.sub.10)aryl; R.sup.

Abstract: Methods of separating the stereoisomers of secondary di- and tri-alcoholic compounds comprise reacting a racemic mixture of the secondary alcohols with an acyl anhydride or an ester in the presence of an enzyme which stereoselectively acylates the (R) site of the alcohol to form the (R) site acyl ester of the alcohol and separating the (S,S) or (S,S,S) secondary alcohol, the (R,S) or (R,S,S) monoacyl ester of the alcohol, the (R,R) or (R,R,S) diacyl ester and/or the (R,R,R) triacyl ester of the alcohol from one another and from the reaction medium.

Abstract: A method for synthesizing a polyester comprises reacting a diester and a dialcohol at approximately ambient temperature in the presence of an enzyme catalyst, preferably a lipase comprising porcine pancreatic lipase. The method is particularly adapted for enantioselective polymerization resulting in an optically active polyester. The polyesters preferably exhibit a weight average molecular weight, Mw, as measured by gel permeation chromatography of at least about 3000.