Microbial desymmetrization of 3-arylglutaronitriles, an unusual enhancement of enantioselectivity in the presence of additives

In the presence of an organic additive such as acetone or β-cyclodextrin or in a biphasic system of hexane and aqueous phosphate buffer, microbial desymmetrization of 3-arylglutaronitriles catalyzed by Rhodococcus sp. AJ270 cells proceeded regiospecifically and enantioselectively to produce S-(+)-3-aryl-4-cyanobutyric acids in high enantiomeric excess. Convenient chemoenzymatic syntheses of optically active R-(−)-4-amino-3-phenylbutyric acid and 4R-(−)-4-phenyltetrahydropyran-2-one are described.