The invention of radical reactions. Part XV.¹ 1 In the light of the results recorded in the present paper we have removed the word "chain" from the title of the series.Some mechanistic aspects of the decarboxylative rearrangement of thiohydroxamic esters

Esters (mixed anhydrides) derived from aliphatic or alicyclic carboxylic acids (RCO₂H) and thiohydroxamic acids 2 or 3 undergo a thermally or photochemically induced radical chain reaction to give sulphides 4 with loss of carbon dioxide. On irradiation at low-temperature however, the chain reaction is essentially supressed. Under these conditions moderate to good yields of dimers R-R are obtained from primary acids. The mechanistic and synthetic implications of these observations are discussed.