In organic solvents, lipase AmanoP catalyzed the asymmetric ring opening of glutaric anhydrides bearing -CH2C1, -CH2F and -OCH3groups at position 3 with methanol and 1-butanol to afford the corresponding monoesters in 70-86% e.e. Optically active <5-valerolactones were synthesized from the monoesters in overall yields of 34-62%.The^-configuration was assigned to the monoesters and the lactones by means of a CDanalysis and chemical correlation. This indicates that the lipase preferentially attacked the pro-R carbonyl group of these anhydrides carrying hetero atoms, in keeping with the trend observed for glutaric anhydrides having simple alkyl substituents. 1H); MSm/z(M+): Calcd. forC6H10O3, 130.0630; Found, 130.0634.

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