摘要：1) From the infrared absorption spectral examination of normal- and iso-dihydrothiamine and related compounds (VII), it was confirmed that the structure of normal- and iso-dihydrothiamine should not be represented by the hitherto used structural formula (I) but by (II) from the fact that these compounds show absorption of an amino group but not of hydroxyl group and absorptions at 1030 and 840 cm-1 of characteristic ring vibration. 2) 3-Benzyl-3a-methyl-perhydrofuro[2, 3-d]thiazole compounds (VII) were synthesized by the reduction of benzylthiazolium compounds (VIII) with lithium aluminum hydride or sodium borohydride, or by the condensation of benzylamine, formaldehyde, and 3-acetyl-3-mercaptopropanol.
