Heterocycles 32. Efficient kinetic resolution of 1-(2-arylthiazol-4-yl)ethanols and their acetates using lipase B from Candida antarctica

Abstract

Abstract In this paper we describe the chemoenzymatic synthesis of new enantiomerically enriched ( R )- and ( S )-1-(2-arylthiazol-4-yl)ethanols and their acetates by enzymatic enantioselective acetylation of the racemic alcohols rac - 2a – d and by methanolysis of the corresponding racemic esters rac -3 a – d mediated by lipase B from Candida antarctica (CaL-B) in non-aqueous media. In terms of stereoselectivity and activity, both procedures, acylation and alcoholysis, gave similar good results (50% conversion, E ≫ 200). The absolute configuration of the kinetic resolution products was determined by a detailed 1 H NMR study of the Mosher's derivatives of ( S )- 2b .