The Photoreaction of 1-Cycloalkenyl Phenethyl Ketone

Abstract The UV irradiation of 1-cyclopentenyl phenethyl ketone in benzene or methanol gave a cyclobutane derivative. The irradiation of 1-cyclohexenyl phenethyl ketone in methanol or in benzene containing either BF3–Et2O or CF3COOH gave a cycloheptanone derivative. The formation of the cycloheptanone derivative requires an acid catalyst.