The photochemistry of o-benzylbenzophenone: A pericyclic cornucopia

Article abstract of DOI:10.1016/S0040-4039(98)00405-5

UV irradiation of the title compound produces cis-1,2- diphenylbenzocyclobutenol quantitatively. While stable at temperatures below 0°, at room temperature it establishes a high enough equilibrium population of its EE o-xylylenol precursor to undergo slow reversion to ketone and rapid reaction with maleic anhydride or oxygen, as well as photoinduced cyclization to the trans cyclobutenol.