Synthesis of ketopyranosyl glycosides and determination of their anomeric configuration on the basis of the three-bond carbon–proton couplings
作者:Gábor Májer、Anikó Borbás、Tünde Zita Illyés、László Szilágyi、Attila Csaba Bényei、András Lipták
DOI:10.1016/j.carres.2007.05.006
日期:2007.8
Anomeric pairs of ketopyranosyl glycosides with various substituents at C(alpha), C(beta) and C(gamma) were synthesized from the corresponding thioglycosides, and the influence of the C(alpha)-C(beta)-C(gamma)-H(gamma) torsion angle and substituent effects on the three-bond carbon-proton couplings was studied. The cis coupling constants range from 1 to 2Hz. The trans couplings are generally as small
由相应的硫代糖苷合成了在Cα,Cβ和Cγ处具有多个取代基的酮基吡喃糖基糖苷对,并研究了Cα-Cβ-Cγ-的影响。研究了H(γ)扭转角和取代基对三键碳-质子耦合的影响。顺式耦合常数范围为1到2Hz。跨耦合通常小至2.3-2.6Hz;反之亦然。然而,对于带有未取代的γ-碳的化合物,测得的反式耦合相对较大(4.8Hz)。与相应的O-糖苷相比,β-位的S-乙基增加了顺式偶联(高达3.2Hz)。