Totally Stereoselective Synthesis of 1,3-Disaccharides through Diels−Alder Reactions
作者:Alessandra Bartolozzi、Stefania Pacciani、Cecilia Benvenuti、Martina Cacciarini、Francesca Liguori、Stefano Menichetti、Cristina Nativi
DOI:10.1021/jo034556r
日期:2003.10.1
A nonclassical, totally stereoselective synthesis of orthogonally protected 1,3-disaccharides is reported. Enantiomerically pure beta-keto-delta-lactones, efficiently obtained from glucal and galactal, are transformed into electron-poor heterodienes and chemo-, regio-, and stereoselectively cycloadded to glycals as electron-rich dienophiles, to directly afford 2-thiodisaccharides. The reductive desulfurization
报道了正交保护的1,3-二糖的非经典的,完全立体选择性的合成。有效地从葡萄糖和半乳糖中获得的对映体纯的β-酮-δ-内酯被转化为电子贫乏的异二烯和化学,区域和立体选择性地加成到乙二醇中,成为富含电子的亲二烯体,直接得到2-硫代二糖。后者的还原脱硫平稳地得到相应的2,2′-二脱氧二糖。