In studies on the glycosylation of 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN) derivatives, O-glycosides of furanose-type KDN were synthesized from benzyl 4, 5, 7, 8, 9-penta-O-acetyl-2-bromo-2, 3-dideoxy-D-glycero-D-galacto-2-nonulopyranosonate under Koenigs-Knorr reaction conditions. The furanoid structures of the KDN moiety were supported by with 1H-NMR experiments, and the reaction was considered as a novel glycosylation with ring contraction, which proceeded via in situ pyranose-furanose rearrangement of the KDN moiety, and subsequent coupling with acceptors.
在对 3-脱氧-D-
甘油-
D-半乳糖-2-壬
磺酸(KDN)衍
生物的糖基化研究中,在柯尼希斯-克诺尔反应条件下,以 4, 5, 7, 8, 9-五-O-乙酰基-2-
溴-2, 3-脱氧-D-
甘油-
D-半乳糖-2-壬磺
吡喃糖酸苄酯为原料合成了
呋喃糖型 KDN 的 O-糖苷。1H-NMR 实验证实了 KDN 分子的
呋喃结构,并认为该反应是一种新型的缩环糖基化反应,是通过 KDN 分子的原位
吡喃糖-
呋喃糖重排以及随后与受体的偶联进行的。