SYNTHESIS AND REACTION OF CYANO-SUBSTITUTED 1,2,4-TRIOXOLANES

Carbonyl oxides, derived from the ozonolyses of vinyl ethers, readily undergo [3 + 2] cycloadditions with acyl cyanides affording the corres ponding cyano-substituted 1,2,4-trioxolanes in isolated yields of 34-8 8%. In competition experiments, a relative order of reactivity of the carbonyl oxide trapping agents was tentatively deduced; trifluoroaceto phenone > alpha,alpha-diphenyl-N-methylnitrone (N-methyldiphenyl-methy lideneamine N-oxide) > benzoyl cyanide > methyl benzoylformate > alpha ,alpha,N-tiphenylimine [N-(diphenylmethylidene)aniline] much greater t han benzaldehyde. As expected from the electron-withdrawing ability of the cyano group, 3-cyano-3-phenyl-1,2,4-trioxolane oxidized not only triphenylphosphine but also methyl p-tolyl sulfide and 2,3-dimethylbut -2-ene very easily.