Abstract
Data presented in the previous paper have demonstrated that in oral administration O, S-bis (ethoxycarbonyl) thiamine (DCET) showed higher blood thiamine levels for a longer time than thiamine hydrochloride. The present investigation was undertaken to seek some compounds possessing a thiamine activity corresponding or more excellent to DCET. Nine S-mono- and O, S-bis-substituted thioalkoxycarbonyl- or thioalkoxythiocarbonyl thiamine derivatives (I〜IX), S-allyloxycarbonyl-O-tetrahydropyranyl-and S-thioallyloxycarbonyl-O-tetrahydropyranyl thiamine (X, XI) were synthesised by the methods analogous to those described previously. It was shown previously that in S-thioalkoxycarbonyl- or S-thioalkoxythiocarbonyl thiamines S→O rearrangement took place either in alkaline or in acidic medium, similarly as in the case of S-alkoxycarbonylthiamines. Based on this method, any substituted O, S-bis-substituted thiamine derivatives could be obtained easily. Some of these compounds synthesised when administered orally showed fairly high blood thiamine levels for a long time, corresponding to that of DCET.
