Isopropyl 3-deoxy-α- D - ribo -hexopyranoside (isopropyl 3-deoxy-α- D -glucopyranoside): evaluating trends in structural parameters
Isopropyl 3-deoxy-α- D - ribo -hexopyranoside (isopropyl 3-deoxy-α- D -glucopyranoside): evaluating trends in structural parameters
复制标题
异丙基3-脱氧-α-D-核糖-吡喃己糖苷（异丙基3-脱氧-α-D-吡喃葡萄糖苷）：评估结构参数的趋势
DOI：
10.1107/s205322962100749x
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Serianni, Anthony S.
中科院分区：
文献类型：
--
作者：
Lin, Jieye;Oliver, Allen G.;Meredith, Reagan J.;Carmichael, Ian;Serianni, Anthony S.
异丙基3-脱氧-α-d-核糖-己基吡喃苷（异丙基3-脱氧-α-d-葡萄糖吡喃苷），C9H18O5, (I)，在室温下从甲醇-乙酸乙酯溶剂混合物中结晶成4C1椅子构象，略微扭曲成C5SC1扭曲船形。比较(I)、甲基α-d-葡萄糖吡喃苷、（II）、α-d-葡萄糖吡喃基-(1→4)-d-葡萄糖醇（麦芽糖醇）、（III）和3-脱氧-α-d-核糖体-六吡喃糖（3-脱氧-α-d-葡萄糖吡喃糖）、（IV）的结构参数表明，醛己基环上的大多数内环和外环键长、价键角和扭转角更受端粒构型、糖苷元结构和/或外环取代基构象的影响，如羟甲基；而不是C3的单脱氧。通过密度泛函理论（DFT）对计算结构(I)c - (IV)c进行计算，证实了(I) - (IV)c晶体结构中观察到的结构效应。外环羟基甲基在(I)和（III）中为间扭式-间扭式（gg）构象（H5抗O6），在（II）和（IV）中为间扭式-反式（gt）构象（C4抗O6）。(I)和（III）中的o -糖苷键构象类似于含有β-（1→4）键的双糖。
Isopropyl 3-deoxy-α-d-ribo-hexopyranoside (isopropyl 3-deoxy-α-d-glucopyranoside), C9H18O5, (I), crystallizes from a methanol–ethyl acetate solvent mixture at room temperature in a 4C1 chair conformation that is slightly distorted towards the C5SC1 twist-boat form. A comparison of the structural parameters in (I), methyl α-d-glucopyranoside, (II), α-d-glucopyranosyl-(1→4)-d-glucitol (maltitol), (III), and 3-deoxy-α-d-ribo-hexopyranose (3-deoxy-α-d-glucopyranose), (IV), shows that most endocyclic and exocyclic bond lengths, valence bond angles and torsion angles in the aldohexopyranosyl rings are more affected by anomeric configuration, aglycone structure and/or the conformation of exocyclic substituents, such as hydroxymethyl groups, than by monodeoxygenation at C3. The structural effects observed in the crystal structures of (I)–(IV) were confirmed though density functional theory (DFT) calculations in computed structures (I)c–(IV)c. Exocyclic hydroxymethyl groups adopt the gauche–gauche (gg) conformation (H5 anti to O6) in (I) and (III), and the gauche–trans (gt) conformation (C4 anti to O6) in (II) and (IV). The O-glycoside linkage conformations in (I) and (III) resemble those observed in disaccharides containing β-(1→4) linkages.