固态糖内酯的构象与结构研究。第二部分。α-D-葡糖糖精-γ-内酯：2-C-甲基-D-核糖-戊糖-1,4-内酯的分子结构。

Conformations and structure studies of sugar lactones in the solid state. Part II. The molecular structure of alpha-D-glucosaccharino-gamma-lactone: 2-C-methyl-D-ribo-pentono-1,4-lactone.

作者信息

Shalaby M A, Fronczek F R, Younathan E S, Williams G J, Straver L H

机构信息

Department of Biochemistry, Louisiana State University, Baton Rouge 70803.

出版信息

Carbohydr Res. 1994 Nov 15;264(2):191-8. doi: 10.1016/s0008-6215(05)80005-9.

DOI:10.1016/s0008-6215(05)80005-9

PMID:7805060

Abstract

The crystal structure of 2-C-methyl-D-ribo-pentono-1,4-lactone (alpha-D-glucosaccharino-gamma-lactone, 1) has been determined by single-crystal X-ray diffraction. The crystals are orthorhombic, space group P2(1)2(1)2(1) with a = 7.7429(6), b = 8.3373(7), c = 11.3258(7) A, V = 731.1(2) A3 (CuK alpha, lambda = 1.54184 A), mu = 10.82 cm-1, Dc = 1.473 g cm-3, and Z = 4. The structure was refined to R = 0.0307 and Rw = 0.0424 for 876 observed reflections. Compound 1 has the D-ribo configuration, in agreement with an earlier deduction from chemical evidence. The lactone ring adopts the 3T2 conformation, with puckering parameters psi = 279.8(9) degrees and q = 0.32(5) A. The orientation of the methyl group about the C-2-C-3 bond is gauche-trans, with the C-6-C-2-C-3-O-3 and C-6-C-2-C-3-C-4 torsion angles being -81.3(2) degrees and 154.7(1) degree, respectively. The molecules are linked in the crystal in a two-dimensional intermolecular hydrogen bonding network that involves all hydroxyl groups as well as the carbonyl oxygen atom.

摘要

通过单晶X射线衍射确定了2-C-甲基-D-核糖-戊糖-1,4-内酯（α-D-葡萄糖氨基-γ-内酯，1）的晶体结构。晶体为正交晶系，空间群P2(1)2(1)2(1)，a = 7.7429(6)，b = 8.3373(7)，c = 11.3258(7) Å，V = 731.1(2) Å³（CuKα，λ = 1.54184 Å），μ = 10.82 cm⁻¹，Dc = 1.473 g cm⁻³，Z = 4。对876个观察反射进行结构精修，得到R = 0.0307，Rw = 0.0424。化合物1具有D-核糖构型，与早期化学证据推导的结果一致。内酯环采用3T2构象，褶皱参数ψ = 279.8(9)°，q = 0.32(5) Å。甲基围绕C-2-C-3键的取向为反式-顺式，C-6-C-2-C-3-O-3和C-6-C-2-C-3-C-4扭转角分别为-81.3(2)°和154.7(1)°。分子在晶体中通过二维分子间氢键网络相连，该网络涉及所有羟基以及羰基氧原子。