Preparation of α and β anomers of various isomeric methyl O-d-galactopyranosyl-d-galactopyranosides. Standards for interpretation of 13C-n.m.r. spectra of d-galactopyranans
作者:Philip A.J. Gorin
DOI:10.1016/s0008-6215(00)80790-9
日期:1982.2
r. resonances of α and β anomers of methyl O - d -galactopyranosyl-β- d -galactopyranosides. In terms of application of these shift values and those of related d -galactobioses to the structural analysis of d -galactopyranans by shift comparisons, some generalizations can be made. For β- d -galactopyranans, the resonances of glycosyloxylated carbon atoms of methyl O -β- d -galactopyranosyl-β- d -galactopyranosides
摘要通过将2,3,4,6-四-O-乙酰基-α-d-吡喃半乳糖基溴化物与适当的部分O-缩合制备甲基O-β-d-吡喃半乳糖基-β-d-吡喃半乳糖苷的四个异构体。甲基β-d-吡喃半乳糖苷的取代衍生物。在溴化汞的存在下,3,4,6-三-O-乙酰基-1,2-O-(1-乙氧基亚乙基)-α-d-吡喃半乳糖与相同的受体反应导致形成α和β β键。因此,有可能分配13个Cn.mr共振的甲基O-d-吡喃半乳糖苷-β-d-吡喃半乳糖苷的α和β端基异构体。在通过移位比较将这些移位值和相关的d-半乳双歧杆菌的值应用于d-半乳糖吡喃聚糖的结构分析方面,可以做出一些概括。对于β-d-吡喃半乳糖,甲基O-β-d-吡喃半乳糖苷-β-d-吡喃半乳糖苷的糖基氧基化碳原子的共振对结构敏感,并且似乎具有典型值,而随着C-1'信号的移位观察到有限的变化。另一方面,为了将结构分配给含有α键的d-吡喃半乳糖,甲基O-α-d-吡喃半乳糖基-