论文部分内容阅读
碳苷是一类糖与苷元以碳碳键相连的化合物。目前常用的合成方法是有机金属试剂法和糖基化法。前者应用范围广泛,但立体选择性较差。后者虽然在应用上受到一定限制,但多数情况下能得到立体选择性的碳苷。Schmidt等人和Williams等人曾分别利用苄基保护糖的亚胺酸酯和吡啶硫醚在Lewis酸催化下和芳香醚反应,得到了立体选择性的碳苷。我们在寻找新的、更有效的糖C_1位离去基团时,发现1-α-三甲硅烷氧基-2,3,4,6-四-O-苄基-D-吡喃葡萄糖(1)和芳香醚反应,同样能立体选择性地得到芳香碳苷。并从理论上讨论了端基效应和碳苷稳定性与糖基化反应机理的关系。
Carbon glycosides are a class of compounds in which sugar and aglycone are linked by carbon-carbon bonds. Currently used synthetic methods are organometal reagent and glycosylation method. The former has a wide range of applications but poor stereoselectivity. Although the latter is limited in application, stereoselective carbon glycosides can be obtained in most cases. Schmidt et al. And Williams et al., Respectively, used stereospecific carbon glycosides by using benzyl protecting sugar imidoesters and pyridine thioethers respectively under Lewis acid catalysis and aromatic ethers. When we looked for a new and more efficient sugar C_1 leaving group, 1-α-trisiloxy-2,3,4,6-tetra-O-benzyl-D-glucopyranose ) And aromatic ethers, the same stereospecific aromatic carbon glycosides can be obtained. The relationship between the end group effect and the stability of glycosylation and glycosylation reaction mechanism was also discussed theoretically.