作者:Giorgio Catelani、Antonino Corsaro、Felicia D'Andrea、Manuela Mariani、Venerando Pistarà、Elisa Vittorino
DOI:10.1016/j.carres.2003.08.001
日期:2003.10
dimethyl acetal derivatives 7 and 14 as key intermediates. The synthesis of enol ethers 7 and 14 has been performed with good yields by base-promoted elimination of acetone or p-toluenesulfonic acid from 2',6'-di-O-benzyl-, and 6'-O-p-toluenesulfonyl-2,3:5,6:3',4'-tri-O-isopropylidenelactose dimethyl acetal, respectively. The epoxidation with MCPBA of 7 and 14 in methanol or dichloromethane furnishes
2,6-二-O-苄基-(9),2-O-苄基-3,4-O-异亚丙基-(19)和2-O-苄基-6-Om-氯苯甲酰基-L-阿拉伯糖基己糖使用4'-脱氧-4'-烯醇和6'-脱氧-5'-烯醇乳糖二甲基乙缩醛衍生物7和14作为关键中间体制备了-5-ulose(20)。通过从2',6'-二-O-苄基-和6'-Op-甲苯磺酰基-2,碱促进的丙酮或对甲苯磺酸的碱促进消除反应,烯醇醚7和14的合成产率很高。 3:5,6:3',4'-三-O-异丙基半乳糖二甲基乙缩醛。在甲醇或二氯甲烷中用MCPBA 7和14进行环氧化可提供C-5'-甲氧基和C-5'-间-氯苯甲酰氧基衍生物,易于以良好的收率转化为L-阿拉伯糖5-酮代己糖9、19和20。