Highly enantioselective biotransformations of 2-aryl-4-pentenenitriles, a novel chemoenzymatic approach to (R)-(−)-baclofen

Catalyzed by Rhodococcus sp. AJ270 microbial cells under mild conditions, a range of racemic 2-aryl-4-pentenenitriles 1 underwent effective hydrolysis to afford excellent yields of enantiomerically pure (R)-(−)-2-aryl-4-pentenamides 2 and (S)-(+)-2-aryl-4-pentenoic acids 3 in most cases. The application of this biotransformation has been shown by a two-step synthesis of (R)-(−)-baclofen.