Studies on Thiamine Disulfide. XIX. On Formation of Hypothiaminic Acids and Related Reactions.

抄録

Refluxing of monosulfoxide (Ia) of O-benzoylthiamine disulfide in aqueous ethanol or an alkaline decomposition of the compound Ia provided a new compound, O-benzoylhypothiaminic acid (II) which is presumed to be an intermediate in the course of formation of O-benzoylthiaminic acid (VI). An alkaline hydrolysis of II afforded hypothiaminic acid (V). These hypothiaminic acids were oxidized to the corresponding thiaminic acids by hydrogen peroxide. From the fact that, in refluxing the compound Ia in aqueous ethanol, O-benzoylthiamine disulfide (III) was formed besides the compound II, it seemed reasonable to assume that the decomposition pathway is disproportionation and the alkaline decomposition is similar hydrolysis to that of carboxylic esters to give the sulfinic acid (II) and thiol (IV).