Semiempirical calculations of the hydrolysis of penicillin G

Abstract A theoretical study of the gas-phase alkaline hydrolysis of penicillin G on the assumption of a B AC2 mechanism is reported. Various semiempirical methods were used to determine the influence of different parameterizations on the process. Among the most salient results obtained, the standard AM1 method predicted opening of the thiazolidine ring to yield the corresponding imine and enamine structures.