Abstract
Oxidation of S-alkylthiamines and S-alkoxycarbonylthiamines, which are difficult to convert to thiamine by sulfhydryl compounds, was investigated. S-alkylthiamines were oxidized with hydrogen peroxide and perbenzoic acid in glacial acetic acid to afford the corresponding sulfoxides and sulfones in accordance with the amount of the peroxide. α-Acyloxysulfide-type thiamine, which was presumed to be produced via the Pummere's reaction, obtained by the reaction of sulfoxide with acid anhydride.
O-Benzoyl-S-ethoxycarbonylthiamine, one of S-alkoxycarbonylthiamines, was oxidized with hydrogen peroxide to give O-benzoylthiaminic acid.
