The cathodic reduction of SO2, dissolved in aprotic solvents, to the anion radical SO2− in the presence of organic halides RX results in the formation of organic sulphones R-SO2-R at appreciable current yields. With dihalides, polymeric sulphones or, as in the case ofo-xylylenedibromide, inner sulphinic esters (sultines) are formed, the latter being easily convertible to the corresponding cyclic sulphones.