Regioselective dihydroarene oxide formation during ortho-hydroxylation of halogenobenzenes by fungi

Abstract

ortho-Hydroxylation of chloro- and bromo-benzene occurred in the presence of growing cultures of the fungi Rhizopus arrhizus, Rhizopus stolonifer, and Cunninghamella elegans. The absence of a primary kinetic isotope effect and the presence of the NIH shift are consistent with dihydroarene oxides being initial metabolites. N.m.r. analysis of the deuterium-labelled o-halogenophenol products suggests that enzyme-catalysed epoxidation occurs preferentially at the 2,3-bond.