Kinetic Resolution of Optically Pure 3-Alkanol by Pseudomonas cepacia Lipase-Catalyzed Transesterification with Vinyl Acetate in Organic Solvent

Abstract

Kinetic resolution of 3-alkanol by Pseudomonas cepacia lipase-catalyzed transesterification has been studied using vinyl acetate as an acetylating reagent, five alcohols and different organic solvents. The optical resolution data did not fit the previously reported theory: the enantioselectivity (E : the enantiomeric ratio for the homocompetitive reaction) showed the maxima against the extent of conversion (c ) in all systems studied. The optical resolution of (S )-3-alkanol with above 95% of enantiomeric excess (ee ) was attained by controlling c , but only a moderate ee was observed in the resolution of (R ) isomer from the racemate, owing to low or moderate enantioselectivity. The resolution of enantiomers with high optical purity was carried out using enantiomerically enriched alcohol: the ee values of the resolved alcohols showed an excellent agreement with those determined by the previously reported equations using the optical resolution data. Based on these observations, optically pure (R )- and (S )-3-alkanols (ee ≥ 99%) were resolved from the racemates in a preparative scale by repeating the transesterification.