D-manno-(3) and L-rhamno-(4) configurations have been efficiently coupled with diverse sugar alcohols (6,8–11) on activation by methyl iodide to obtain the α-linked disaccharides (7,12–19). Coupling of donor 1 with the disaccharide acceptor 20 and the disaccharide donor 5 with 8 to obtain α-linked trisaccharides 21 and 22 is also described. A possible mechanism for the α-selectivity is also discussed
描述了一种新的,实用的,立体选择性糖苷化方法,其中每个
D-葡萄糖-(1),
D-半乳糖-(2),D-
甘露聚糖-(- )的O-苄基化2-
吡啶基1-
硫代-α/β-己
吡喃糖基3)和
L-鼠李糖(4)构型已通过甲基
碘活化与各种糖醇(6,8-11)有效偶联,获得了α-连接的二糖(7,12-19)。供体1与二糖受体20的偶联,以及二糖供体5与8的偶联,以获得α-连接的三糖21和22也进行了描述。还讨论了α选择性的可能机理。