Alkyloxytris(dimethylamino)phosphonium salts. Part 21. Anomeric hydroxy-group activation of 2,3:4,6-di-O-isopropylidene-α-<scp>D</scp>-mannopyranose, thioglycosylation and glycosylation
作者:Françoise Chretien、Yves Chapleur、Bertrand Castro、Bernard Gross
DOI:10.1039/p19800000381
日期:——
anomeric form of the corresponding alkoxytris(dimethylamino)phosphonium chloride. The condensation of aromatic thiols with this salt leads to β-thiomannosides by an SN2 process and the condensation of alcohols, preceded by the action of silver salts in order to avoid the formation of the glycosyl chlorides, yields a mixture of α- and β-mannosides.
四氯化碳和三(二甲基氨基)膦在低温下对2,3:4,6-二-O-异亚丙基-α - D-甘露聚糖的作用提供了相应的烷氧基三(二甲基氨基)amino的α端基形式。芳香族硫醇与该盐的缩合会通过S N 2过程生成β-硫代甘露糖苷,而醇的缩合随后是银盐的作用,以避免形成糖基氯化物,生成α-和N-的混合物。 β-甘露糖苷。