Preparation of novel phenylfuran-based cyanohydrin esters: lipase-catalysed kinetic and dynamic resolution

Abstract

A series of novel ( R)-5-phenylfuran-2-yl cyanomethyl butanoates were prepared by Pseudomonas cepacia lipase-catalysed dynamic kinetic resolution in toluene. The method exploits a basic resin both for the racemization and formation of phenylfuran-based cyanohydrins and for the decomposition of acetone cyanohydrin in one-pot with enzymatic enantioselective acylation using vinyl butanoate. The lipase-catalysed methanolysis of racemic 5-phenylfuran-2-yl cyanomethyl butanoates in toluene with E ≫100 was shown to be usable when the corresponding ( S)-butanoates are needed. Candida antarctica lipase A provided racemic cyanohydrin butanoates with quantitative chemical yields under mild conditions.