Lipase YS-Catalyzed Enantioselective Transesterification of Alcohols of Bicarbocyclic Compounds

Abstract

Abstract Lipase YS-catalyzed enantioselective acylations of (1RS, 2RS, 4RS, 5RS)-bicyclo[2.2.1]heptane-2,5-diol, (1RS, 2SR, 4RS, 5SR)-bicyclo[2.2.2]octane-2,5-diol, (1RS, 2RS, 4RS, 5RS)-bicyclo[2.2.2]octane-2,5-diol, and (1RS, 2SR, 5RS, 6SR)-bicyclo[3.3.1]nonane-2,6-diol with aryl acetates such as phenyl acetate, 1-naphthyl acetate, and 2-naphthyl acetate gave the monoacetates and the diols in optically active forms. The optical purities of (+)-(2R, 5R)-2-acetoxybicyclo[2.2.1]heptan-5-ol, (−)-(1S, 2R, 4S, 5R)-2-acetoxybicyclo[2.2.2]octan-5-ol, and (+)-(2R, 6R)-2-acetoxybicyclo[3.3.1]nonan-6-ol obtained using phenyl acetate were higher than those of the monoacetates which have been resolved by PLE-catalyzed hydrolysis of the corresponding racemic diacetates. Enzymic acylations of the diols using phenyl esters such as phenyl propanoate, phenyl butanoate, and phenyl octanoate as acylating agents gave the corresponding monoesters, which showed nearly the same enantiomeric excess value as the acetates. A simple model for predicting which enantiomer of racemic alcohols is acylated preferentially by lipase YS-catalyzed enantioselective transesterification is proposed on the basis of the results obtained here.