Jones oxidation of suitably protected allyl beta-D-galactopyranosides and subsequent esterification were reinvestigated. Partial deprotection of the resulting D-galacturonic acid derivatives afforded compounds suitable for transformation into glycosyl acceptors. The synthesis of 2-, 3-, and 4-trityl ethers, relying on efficient differential protecting-group strategies, is described. Trityl-cyanoethylidene
重新研究了适当保护的烯丙基β-D-
吡喃半
乳糖苷的琼斯氧化反应和随后的酯化反应。所得
D-半乳糖醛酸衍
生物的部分脱保护得到适合转化为糖基受体的化合物。描述了依靠有效的差异保护基策略合成2-,3-和4-三苯甲基醚。这些三苯甲基醚的三苯甲基-
氰基亚乙基缩合,导致被保护的二糖单元β-D-GalpA-(1-> 2)-D-GalpA和beta-D-GalpA-(1-> 3)-GalpA具有较高的证明了立体选择性。还制备了β-D-GalpA-(1→4)-D-GalpA二糖。