THE ENANTIOMER RATIO STRONGLY DEPENDS ON THE ALKYL PART OF THE ACYL DONOR IN TRANSESTERIFICATION WITH LIPASE-B FROM CANDIDA-ANTARCTICA

Three secondary alcohols, 1-phenoxy-, 1-phenylmethoxy- and 1-(2-phenyl ethoxy)-2-propanol, have been resolved by transesterification with the acyl donors 2-chloroethyl butanoate, 2,2,2-trichloroethyl butanoate, vinyl butanoate and butanoic anhydride using lipase B from Candida ant arctica as catalyst in hexane. The enantiomer ratio E, which was calcu lated on the basis of a ping-pong bi-bi mechanism, was highest when 2- chloroethyl butanoate was used as acyl donor, however the reaction was reversible. It was shown that the E-value increased when the amount o f 2,2,2-trichloroethyl butanoate was reduced. It is also indicated tha t butanoic anhydride and vinyl butanoate make the lipase less specific probably by acylation. Copyright (C) 1996 Elsevier Science Ltd