Thermolytic reactions of esters. Part XI. Vapour-phase thermolysis of allyl methyl oxalate and allyl phenyl oxalate and its relevance to the thermochemistry of oxycarbonyl radicals

Abstract

The title compounds homolyse in the vapour phase (flow system; 400–500°). Of the intermediate ·CO₂R radicals those with R = methyl or allyl decarboxylate whereas the phenyl analogue loses carbon monoxide. Thermo-chemical aspects are considered; it is concluded that the carbon dioxide and carbon monoxide formed in photolysis or thermolysis of liquid oxalates in the presence of iodine do not arise through decomposition of ·CO₂R radicals.