Enzymatic resolution of 2-fluoro-2-arylacetic acid derivatives

Abstract

Optical resolutions of 2-fluoro-2-arylacetic acids, ArC *FRCOOH (R=CN, H, and Me), were performed by enantioselective hydrolysis of the corresponding esters using Candida rugosa lipase (CRL). The enantioselectivity of commercial CRL toward the esters was greatly improved when commercial CRL was treated with 2-propanol solution. In the enantioselective hydrolysis of these esters, as represented by ArC * SMCOOR ( S and M are small and medium substituents, respectively), the active site of the 2-propanol-treated CRL recognized fluorine as S in both PhCF(CH 3)COOR and p-TolCF(CN)COOR but recognized fluorine as M in PhCHFCOOR.