The hexasaccharide O-antigen of Vibrio cholerae O139 was synthesized in its protected form from thioglycosides and glycosyl bromides as glycosyl donors by a stepwise and blockwise approach. The synthesis was designed to permit a global, one-step deprotection (H2, Pd/C). It allows the transformation of 15 functionalities in one operation, namely the removal of ten benzyl protecting groups, the removal of a trichloroethyl phosphate protecting group, the conversion of two N-trichloroacetyl into N-acetyl groups, a bromomethyl into a methyl group, and the conversion of an azido into an amino group.
                                    通过逐步和分块的方法,以
硫代糖苷和
溴化糖苷为糖基供体,合成了霍乱弧菌O139的六糖O抗原。该合成设计为一步整体脱保护(H2,Pd/C)。它允许在一次操作中转换15个官能团,即去除10个苄基保护基团,去除一个三
氯乙基磷酸酯保护基团,将两个N-三
氯乙酰基转化为N-乙酰基,将一个
溴甲基转化为甲基,并将一个
叠氮转化为
氨基。