Kinetic Resolution of Enantiomers in Enantiomerically Enriched 2-Alkanol by Pseudomonas cepacia Lipase Catalyzed Transesterification with Vinyl Acetate in Organic Solvent

Abstract

Kinetic resolution of (R )- and (S )-2-alkanols by Pseudomonas cepacia lipase catalyzed transesterification has been studied using vinyl acetate as an acetylating reagent, six 2-alkanols and three organic solvents. The optical resolution of (S )-2-alkanol with enantiomeric excess (ee ) >95% was attained by controlling the extent of conversion, but (R )-2-alkanol with ee>95% could not resolved from the racemate due to the moderate enantioselectivity. New equations as functions of the optical resolution data were introduced for predicting the ee values of enantiomers resolved by the transesterification with enantiomerically enriched 2-alkanol and they were experimentally verified: the predicted and experimentally obtained ee values showed an excellent agreement in all systems studied. Based on these observations, optically pure (R )- and (S )-2-alkanols (ee≥99%) were resolved from the racemates in a preparative scale by repeating the transesterification.