The photosensitised oxidation of benzyl ethyl sulfides in and the 3-cyclohexenyl sulfide give the corresponding ketone (the latter in a low yield), but the ฮฑ-methylbenzyl aprotic solvents (benzene or acetonitrile) gives the corresponding aldehydes under mild conditions. This is a sulfide gives the sulfoxide as the main product. The rate for singlet oxygen quenching and for chemical reaction have general reaction which applies to benzyl derivatives containing either electron-donating or electron-withdrawing been measured for representative benzyl sulfides. The reaction is discussed in the frame of the currently accepted substituents and furthermore to hetero analogues such as 2pyridinylmethyl sulfide (not to the 3-indolylmethyl sulfide, mechanism for sulfide photooxygenation. The key step for oxidative C-S bond cleavage appears to be hydrogen since reaction at the heterocycle moiety competes) as well as to allyl sulfides. In a protic solvent (methanol) these sulfides transfer from the activated ฮฑ position in the first formed intermediate, the persulfoxide. This reaction is inhibited in give the sulfoxides instead (except for the nitrobenzyl derivatives, where the aldehyde remains the major product).
methanol where the persulfoxide is hydrogen-bonded. Among the ฮฑ-substituted sulfides tested, the ฮฑ-phenylbenzyl [a] Department of Organic Chemistry, University of Pavia, small (e.g. 0.5%) amount was added the products were the viale