The invention of radical reactions

Irradiation with visible light of N-hydroxy-2-thiopyridone esters 1 in the presence of sulphur dioxide gave the corresponding thiosulphonates 4 in good yield. These could be converted to sulphones 5 by treatment with KOH and an alkylating agent. Alternatively, exposure to sulphuryl chloride followed by a primary or secondary amine afforded sulphonamides 6.