Synthesis of dihydropyrrole derivatives by copper-catalyzed cyclization of γ,δ-unsaturated ketone O-methoxycarbonyloximes

2-Bromomethyl-3,4-dihydro-2H-pyrroles are prepared from gamma, delta-unsaturated ketone O-methoxycarbonyloximes by treatment with a catalytic amount of CuBr.SMe2 and LiBr.