Photolysis of sulphur-containing nitrones. Support for a methyleneoxaziridine radical intermediate and formation of new heterocycles

Abstract

The products of photolysis of N-diphenylmethylene-1-ethylthioethyl-, -thiolan-2-yl-, -thiacyclohexan-2-yl-, and -1,4-oxathian-3-yl-amine N-oxides are described. These products are interpreted as arising from alkylidene-(diphenylmethylene)amine N-oxyl radicals of a type previously identified. The nitrones with cyclic N-substituents form oxaziridines and new ring-expanded heterocycles, e.g. 5,6-dihydro-4H-1,2-thiazine from the thiolanyl nitrone. This observation supports the intermediacy of methyleneoxaziridine radicals.