Lipase-catalyzed enantioselective ring opening of unactivated alicyclic-fused beta-lactams in an organic solvent.

[reaction: see text] A highly efficient and very simple method was developed for the synthesis of enantiopure beta-amino acids (e.g. cispentacin) and beta-lactams through the enzyme-catalyzed enantioselective ring opening of unactivated alicyclic beta-lactams in organic media. High enantioselectivity (E > 200) was observed when the Lipolase (lipase B from Candida antarctica)-catalyzed reactions were performed with H(2)O (1 equiv) in diisopropyl ether at 60 degrees C. The resolved products, obtained in good chemical yield (36-47%), could be easily separated.