核苷研究 Ⅱ.苄基糖核苷的立体选择性合成

Studies on Nucleosides Ⅱ. Stereoselective Synthesis of Perbenzylated Sugar Nucleosides

1-(2,3,4,6-O-四苄基吡喃糖基)-三氟乙酸酯或三氯乙酸酯在无水四氯化锡存在下与一些具有代表性的硅醚保护的碱基或者含氮杂环化合物反应,合成了一系列新的苄基糖苷。对三氟乙酰氧基、三氯乙酰氧基作为新的离去基在核苷合成中的反应活性、立体选择性和反应收率进行了讨论。

The reaction of 1-(2, 3, 4, 6-O-tetrabenzylpyranosyl)-trifluoroacetates or trichloroacetates with various representative silylated bases and nitrogen containing heterocycles in the presence of SnCl_4 as catalyst were performed, and a series of new perbenzylated sugar nucleosides have been synthesized. The stereoselectivities, reactivities and yield of glyeosylation reaction using trifluoroacetoxy and trichloroacetoxy group as new efficient leaving groups in the synthesis of nucleosides were discussed.