TETRACHLOROCYCLOPENTADIENONE O-OXIDE, A FACILE OXYGEN-ATOM-TRANSFER REAGENT - THE DISPROPORTIONATION OF CYCLOALKYLDIOXYL RADICALS

Photolysis of tetrachlorodiazocyclopentadiene (1) in oxygen-saturated hydrocarbon solvents results in the transient formation of tetrachloro cyclopentadienone O-oxide (3). This rapidly decomposes, giving rise to products derived from oxidation of the hydrocarbons. Cyclopentane, cy clopentene, cycloheptane, cycloheptene, cycloheptatriene, and indene h ave been studied. Cycloheptatriene and indene gave only low yields of tractable products, but the others gave the corresponding ketones and secondary alcohols as the major products. Although yields varied consi derably, the ketone and alcohol products were always obtained, within experimental error, in a 1 : 1 molar ratio. This observed product rati o supports the disproportionation of cycloalkyldioxyl radicals as a cr ucial step.