3-O-isopropylidene-beta-D-erythrofuranoside and methyl 2,3-O-isopropylidene-beta-D-ribofuranoside was achieved using 4-O-acetyl-2,3-O-carbonyl-alpha-L-rhamnopyranosyl bromide and Ag2O as a promoter. Deprotected disaccharides beta-L-Rhap-(1-->3')-beta-D-Apif-OMe and beta-L-Rhap-(1-->3')-beta-D-Ribf-OMe were compared to their alpha-rhamnosyl isomers which were prepared using conventional Helferich glycosylation.
使用4-O-乙酰基-2可实现甲基2-C-羟甲基-2,3-O-异亚丙基-β-D-
呋喃呋喃糖苷和甲基2,3-O-异亚丙基-β-D-
呋喃呋喃糖苷的β-
鼠李糖基化反应, 3-O-羰基-α-
L-鼠李糖基
溴化物和
Ag2O作为
促进剂。将脱保护的二糖β-L-Rhap-(1-> 3')-β-D-Apif-OMe和β-L-Rhap-(1-> 3')-β-D-Ribf-OMe与它们的α-
鼠李糖基异构体,它们是用常规的Helferich糖基化制备的。