Abstract
Synthesis of an asymmetric disulfide, S-(3-acetylthio-7-carbomethoxyheptyl) S'-benzyl disulfide, was attempted in a couple of ways. The condensation of sodium 3-acetylthio-7-carbomethoxyheptyl thiosulfate (the Bunte salt) and benzylmercaptan achieved preferably the purpose. Another attempt for the synthesis lay on reaction of S, S'-(3-acetylthio-7-carbomethoxyheptyl) thiolsulfinate and benzylmercaptan. But the preparation method of the precursor (the thiolsulfinate) involving replacement of the bromine atom in 3-bromo-7-carbomethoxyheptyl disulfide by the acetylthio group as an intermediate step was found inadequate for the purpose, because the replacement accompanied rearrangement of the disulfide linkage to the carbon atom carrying the bromine atom. However the observations were derived from the synthetic study of an oily product, the benzyl derivative, which could not be completely purified. Therefore the observations were confirmed also in synthesis of S-(3'-acetylthio-7'-carbomethoxyheptylthio) thiamine and successfully established. Additionally two synthetic methods of α-lipamide were reported.
