Novel Self-Coupling Reaction of Cyclic Ketones under a High-Pressure Mercury Lamp.

Abstract A novel self-coupling reaction in alcohol or hexane-water of cycloalkanone (cycloheptanone, cyclooctanone, and cyclododecanone) with irradiation under a high-pressure mercury lamp yielded the corresponding pinacol-type compound in good yields. In the case of cyclohexanone, 2-methyl-, 2-phenyl-, 4-methylcyclohexanone, 5α- and 5β-cholestan-3-one, the pinacol derivatives were not obtained and the dimethyl acetals were given.