irradiation of organic disulfides in aldehyde solvents resulted in the reductive fission of the S–S linkage, giving an equimolar mixture of the corresponding thiol and the thiol acylate in a good yield. The cyclic disulfides gave mono S-acylated dithiols. The reaction proceeded by means of the photo-initiated radicalchainmechanism, and AIBN (azobisisobutyronitrile) effected the same reaction under thermal