Isopropylidenation of maltitol by using excess 2, 2-dimethoxypropane (DMP) and p-toluenesulfonic acid in N, N-dimethylformamide at room temperature for 15 h yielded four acetals which were designated 1 to 4 in the order of decreasing Rf value on thin layer chromatography. After column chromatography on silica gel, compounds 1-4 were separated as 4, 6 : 1', 2' : 5', 6'-triacetal (1, 14%), 4, 6 : 2', 3' : 5', 6'-triacetal (2, 40%), 1', 2' : 5', 6'-diacetal (3, 4%), and 2', 3' : 5', 6'-diacetal (4, 12%), respectively. Excess DMP or prolonged reaction time results in an acetal migration from 1', 2'-to 2', 3'-positions. The reaction and the yields of 1-4 were investigated by high performance liquid chromatography analysis of the benzoylated acetals. 2', 3'-Di-O-benzylmaltose and 3-O-α-D-glucopyranosyl-β-L-gulopyranose were synthesized after chemical modification of 2 and 4, respectively. Thus, maltitol acetals have a potential value in the synthesis of disaccharides with an α-glycosidic linkage.
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