ABSTRACT
The photochemistry of organosulfur compounds in general has been the subject both of annual reports and of timely scattered reviews. Light-induced reactions of specific chromophores, such as sulfoxides and sulfones, thiocarbonyl compounds, and thiols have been discussed in more detail, as has the photochemistry of thiophenes and certain other specific ring systems. Irradiation of the parent compound in benzene or acetonitrile produces one photodimer selectively, while irradiation in the solid state affords the head-to-head, synthesis dimer exclusively. An alternative explanation would be that only irradiation with wavelengths corresponding to the chromophore’s absorption tail induces a single-crystal to single-crystal transformation. Both intermolecular and intramolecular enone/olefin photocycloadditions have gained increasing importance in organic syntheses. The photochemical behavior of 2,3-dihydro-4H-thiin-4-ones resembles strongly that of cyclohept-2-enones.
