We report a very high yielding first total synthesis of trisaccharide 5, α-D-Rhap-(1→3)-α-D-Rhap-(1→4)-α-D-Galp, corresponding to the repeating unit 1 of an O-polysaccharide present in the lipopolysaccharide of clinical isolate of Burkholderia cepacia. The approach included two successive glycosylations, based on D-rhamnosyl trichloroacetimidate donors 12 and 14. The oligosaccharide5 has been further functionalized by photochemical coupling or cross-metathesis with non-natural amino acid derivatives. Trisaccharidylamino acids 16 and 17 are now available, with the aim of preparing a novel synthetic carbohydrate-based vaccine.
我们首次成功合成了三糖5,α-D-Rhap-(1→3)-α-D-Rhap-(1→4)-α-D-Galp,其产量非常高,与伯克霍尔德氏菌临床分离株脂
多糖中O-
多糖的重复单元1相对应。该方法包括基于D-
鼠李糖基三
氯乙
酰亚胺供体12和14的两次连续糖基化。通过光
化学偶联或与非天然
氨基酸衍
生物的交叉复分解,
寡糖5进一步被官能化。三糖基
氨基酸16和17现已可用,目的是制备一种新型的合成
碳水化合物疫苗。