Photoinduced C-C bond cleavage in dithiane-carbonyl adducts: a laser flash photolysis study.

Molecular fragmentations induced by oxidative electron transfer present a fascinating theoretical challenge and generate a great deal of interest due to their potential applications. It is well-known, for example, that in vicinal diols, amino alcohols, and amino ethers, C-C bonds weakened by photoinduced electron transfer cleave efficiently and selectively. Mechanistic aspects of this cleavage have been studied extensively by several research groups.1 In contrast, such C-C fragmentations in analogous organosulfur systems have not been studied in depth, and we attribute the lack of experimental data to the propensity of organosulfur systems to cleave the C-S bond rather than the C-C bond. Recently we reported a photosensitized fragmentation of dithiane-carbonyl adducts, eq 1.2 This process repre-