The changing face of arene oxide oxepine chemistry

Improved methods of arene oxide synthesis by direct oxidation of arenes, and by multistep conversion of vicinal cis-diol and halohydrin precursors, provide entry to a new range of heterocyclic arene oxides (benzofuran, benzothiophene, indole, quinoline, isoquinoline, acridine). Factors which determine both the rate of interconversion and the equilibrium ratio of arene oxide-oxepine tautomers have been elucidated. Recognition that enzyme mediated epoxidation can occur on arene oxide, oxepine, phenol and trans-diol, metabolites of arenes has led to renewed interest in the biological effects of these novel epoxide metabolites.