高效简便的合成纯β构型全乙酰化保护糖缀合物的方法(英文)

High Efficient and Simple Route to Synthesize Per-O-acetyl-β-glycoside

经由路易斯酸BF_3·Et_2O催化全乙酰化糖缀合物合成反应中,只有纯β构型全乙酰化保护糖因其反应中邻基参与效应可以参与反应过程.基于此种机理,为了能得到更多纯β构型全乙酰化保护糖以提高总路线的产率,需要探索出高效糖全乙酰化保护反应.通过对所待选的众多非金属绿色催化剂进行对比,无水醋酸钠因其产率高、构型选择性好被证实是最为理想的糖全乙酰化催化剂.在得到糖全乙酰化产物后,由于不同构型的溶解能力不同,对其进行重结晶可以得到单一β构型的糖全乙酰化产物.基于以上反应,找到了一条高效简便高产率且得到纯β构型全乙酰化保护糖缀合物的合成路线.

In the route to synthesize per-O-acetyl-β-glycoside catalyzed by Lewis acid BF_3·Et_2O,only the per-O-acetyl-β-glycosyl acetate because of the neighboring group assistance can engage into the reaction.Based on this phenomenon,the high efficient peracetylation has to be explored in order to gain more per-O-acetyl-β-glycosyl acetate.Among available nonmetallic and green catalysts with the ability of promoting the peracetylation, the anhydrous sodium acetate has been proved to efficiently catalyze acetylation in satisfying proportion. To gain pure anomericβ-acetate,the product can be purified by recrystallization because of the different solubility betweenαandβmixtures.Through the study of the methodology above,a high efficient and simple route to synthesize per-O-acetyl-β-glycoside in good yield is delineated.