Stereoselective Access to the β-<scp>D</scp>-<i>N</i>-Acetylhexosaminyl-(1→4)-1-deoxy-<scp>D</scp>-nojirimycin Disaccharide Series Avoiding the Glycosylation Reaction
作者:Lorenzo Guazzelli、Giorgio Catelani、Felicia D'Andrea、Tiziana Gragnani、Alessio Griselli
DOI:10.1002/ejoc.201402555
日期:2014.10
-methoxy-2-methylethyl)-lactose dimethyl acetal] as starting material. The synthetic process is based on the transformation of the reducing unit of suitably protected β-D-hexosaminyl-(14)-aldehydo-D-glucose dimethyl acetal disaccharides into a deoxynojirimycin derivative. Key steps of the synthesis are: (a) the selective oxidation of the 5-position of the D-glucose unit, (b) release of the aldehydo
β-D-GlcNAc-、β-D-GalNAc-、β-D-ManNAc-和β-D-TalNAc-(14)-DNJ亚氨基糖二糖的合成已经实现,避免了糖基化反应,使用混合乳糖的四丙酮化物 [2,3:5,6:3',4'-三-O-异亚丙基-(6'-O-2-甲氧基-2-甲基乙基)-乳糖二甲基乙缩醛]作为原料。合成过程基于将适当保护的 β-D-己糖胺基-(14)-醛-D-葡萄糖二甲基乙缩醛二糖的还原单元转化为脱氧野尻霉素衍生物。合成的关键步骤是:(a) D-葡萄糖单元 5-位的选择性氧化,(b) 醛功能的释放,(c) 1,5-二羰基二糖中间体的双还原氨基环化, (d) 完全脱保护。