Synthesis of dihydropyrrole and pyrrole derivatives by radical cyclization of γ,δ-unsaturated ketone O-acetyloximes

Treatment of gamma,delta-unsaturated ketone O-acetyloximes with a catalytic amount of 1,5-naphthalenediol or hydroquinone. acetic acid, and 1,4-cyclohexadiene affords various dihydropyrrole and pyrrole derivatives via radical cyclization induced by one-electron reduction of the oximes.