Bh. Hoff et al., THE ENANTIOMER RATIO STRONGLY DEPENDS ON THE ALKYL PART OF THE ACYL DONOR IN TRANSESTERIFICATION WITH LIPASE-B FROM CANDIDA-ANTARCTICA, Tetrahedron : asymmetry, 7(11), 1996, pp. 3187-3192
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