Acid-catalyzed dehydrative cyclization of 4-(d-galacto-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole. Synthesis and anomeric configuration of d-lyxo-C-nucleoside analogs
作者:Mohammed A.E. Sallam、Somaya M.E. Abdel Megid、Leroy B. Townsend
DOI:10.1016/s0008-6215(00)00251-2
日期:2001.1
20% methanolic sulfuric acid afforded the anomeric pairs of nucleosides, 4-(alpha-D-lyxopyranosyl)-2-phenyl-2H-1,2,3-triazole (major component) and its beta-anomer, as well as 4-(alpha-D-lyxofuranosyl)-2H-1,2,3-triazole and its beta-anomer. The four anomeric C-nucleosides were separated by chromatography, and their structure and anomeric configuration were determined by periodate oxidation, acylation
4-(D-半乳糖-戊醇-1-基)-2-苯基-2H-1,2,3-三唑与20%甲醇的硫酸脱水制得核苷异头对,4-(α-D-lyxopyranosyl )-2-苯基-2H-1,2,3-三唑(主要成分)及其β-端基异构体,以及4-(α-D-lyxofura呋喃糖基)-2H-1,2,3-三唑及其beta -异头物。通过色谱分离四个异头C-核苷,并通过高碘酸盐氧化,酰化,NMR谱以及质谱确定其结构和异头构型。旋光性产生的端基异构体分配与最终结构分配不符,这违反了哈德逊等旋规则。NOE研究和X射线衍射测量证实了端基异构体的构型。