The invention of radical reactions. Part XVIII. Decarboxylative radical addition to arsenic, antimony, and bismuth phenylsulphides - a novel synthesis of nor-alcohols from carboxylic acids

Carbon centered radicals obtained by decarboxylative transformation of suitable thiohydroxamate esters react with group Va trisphenyl-sulphides to give intermediates of general formula R-M(SPh)₂ (M = As, Sb, Bi). These react spontaneously with air to give the corresponding alcohols. This procedure is especially useful in the case where M=Sb. It is thus sufficient to stir the thiohydroxamate ester with tris(phenylthio)-antimony under air to obtain the nor alcohol directly and in high yield. The intermediate organometalloid could also be oxidised with nitrogen dioxide to give the expected nitroalkane albeit in only modest yield. The corresponding organobismuth intermediate derived from 3, 3-diphenylpropionic acid could actually be isolated thereby providing strong evidence for the proposed mechanism.