Molecule-induced homolysis versus "concerted oxenoid oxygen insertion" in the oxidation of organic compounds by dimethyldioxirane

Evidence for a molecule-induced homolysis of dimethyldioxirane by several classes of organic compounds (alkanes, alkenes, ethers, alcohols, aldehydes, iododerivatives) is reported. Carbon-centered radicals, arising from alkanes, ethers, and aldehydes, are trapped by CBrCl3 or protonated quinolines. The dramatic influence of oxygen in these reactions, as well as the formation of products of induced homolysis of the dioxirane by carbon-centered radicals (CH4, CH3OH, CH3COOCH3, ROCOCH3, CH3COOCH2COCH3), strongly supports a radical mechanism. With alkenes and iodo derivatives the induced homolysis would lead to diradical intermediates, whose very fast fragmentation would prevent detection, but circumstantial evidence supports a radical mechanism.