TETRACHLOROCYCLOPENTADIENONE O-OXIDE, A FACILE OXYGEN-ATOM TRANSFER REAGENT - THE OXIDATION OF CYCLOHEXANE

Previous spectroscopic studies with low temperature matrices identified the carbonyl oxide tetrachlorocyclopentadienone O-oxide (4) as a potentially efficient O atom donor. It has now been shown that the photolysis of tetrachlorodiazocyclopentadiene (2) in O-2-saturated cyclohexane gives good yields of the oxidation products cyclohexanol and cyclohexanone. The intermediacy of the carbonyl oxide 4 could not be demonstrated conclusively, but the experimental evidence makes it highly probable. Yields of the products cyclohexanol and cyclohexanone were the highest so far achieved in a photo-oxidation of this type. Photo-oxidation of cyclohexane could be efficiently achieved with the neat liquid or in CCl4 solutions at concentrations down to about 10% of the hydrocarbon. A plausible mechanism for these photo-oxidations has been proposed.