Enzymatic resolution of racemic secondary alcohols by lipase B from Candida antarctica

Abstract

Chiral intermediates S-(+)-2-pentanol and S-(+)-2-heptanol were prepared by a lipase-catalyzed enzymatic resolution process. Among various lipases evaluated for the stereoselective acylation of racemic alcohols, lipase B from Candida antarctica catalyzed the acylation of the undesired enantiomer of racemic alcohols leaving the desired S-(+)-alcohols unreacted. A reaction yield of 43-45% and an enantiomeric excess (e.e.) of >99% were obtained for S-(+)-2-pentanol or S-(+)-2-heptanol when the reaction was carried out using vinyl acetate or succinic anhydride as acylating agent. In an alternative process, an enantioselective hydrolysis of 2-pentyl acetate was demonstrated using lipase B giving S-(+)-2-pentyl acetate and R-(-)-2-pentanol. A reaction yield of 45% and an e.e. of 98.6% were obtained for S-(+)-2-pentyl acetate.