利用三种方法合成偏诺皂甙类化合物

Synthesis of Pennogenyl Saponins via Three Methods

利用三种重要的糖苷化方法,合成了6个偏诺皂甙类化合物(7～12).在三种合成方法中,分别选择了单糖及二糖的卤苷供体、三氯亚胺酯供体及硫苷供体(1～6)以考察它们与受体偏诺皂甙元的反应结果.利用偏诺皂甙元在3位和17位羟基上的位阻差异,使偏诺皂甙元17位羟基在不被保护的情况下与每种糖供体只在其3位羟基发生选择性反应.

The pennogenyl saponins （7-12） were synthesized by using three important methods of glycosylation. As donors（1-6）, glycosyl halide, trichloroimidate and thioglycoside were chosen to react with the acceptor pennogenin to investigate the results of these reactions. In these reactions the difference of steric hindrance between 3-OH and 17-OH of pennogenin was utilized skillfully and only 3-hydroxyl group of pennogenin could be connected with each kind of donors selectively and there was no reaction at 17-hydroxyl group which had no protection. The characteristic above makes it convenient to synthesize the compounds of pennogenyl saponins.