An efficient route for the synthesis of orthogonally protected D-galactosamine thioglycosides via one-pot double serial and double parallel displacements of the D-mannosyl-2,4-bis-trifluoromethanesulfonates by azide and nitrite ions is described. These building blocks were utilized to synthesize the rare disaccharide moiety of the zwitterionic polysaccharide of Bacteroides fragilis and the selectively protected Tn antigen.
通过
叠氮离子和
亚硝酸离子对
D-甘露糖基-2,4-双
三氟甲磺酸酯进行单锅双串联和双并联置换,描述了一条合成正交保护
D-半乳糖胺
硫代糖苷的有效路线。利用这些结构单元合成了脆弱拟杆菌齐聚物
多糖的稀有
双糖分子和选择性保护的 Tn 抗原。