Substituent and solvent effects on the photosensitized oxygenation of 5,6-dihydro-1,4-oxathiins. Intramolecular oxygen transfer vs normal cleavage of the dioxetane intermediates
The reaction of singlet oxygen with variously substituted oxathiins 1 affords dicarbonyl compounds 4 and/or ketosulfoxides 7 and 8 depending on the nature of the substituent at C3 and on the reaction conditions. The normal fragmentation of dioxetanes 2 to