Thermolytic decomposition of benzylic dialkoxy disulfides

Dialkoxy disulfides have been used as an alkoxy radical source under photolytic conditions. In addition, this class of disulfide thermally decomposes to deliver S2 to dienes. We examined benzylic dialkoxy disulfides (X–Ph–CH2–O–S–S–O–CH2–Ph–X) under thermolytic conditions and observed that the rates of decomposition are related to Swain and Lupton’s field constant, F . In addition, the observed non 1:1 ratio of alcohol to aldehyde reaffirms Harpp’s-postulated cage mechanism. We have shown that the ratio is dependant upon the substituent present which can enhance the pi-stacking ability with the solvent, and thus favor diffusion out of the solvation cage yielding the non 1:1 ratio observed.