A. Neuman, D. Avenel, F. Arène
1980
Citations
1
Influential Citations
14
Citations
Journal
Carbohydrate Research
Abstract
Abstract The crystal structure of methyl 3- O -α- d -glucopyranosyl-α- d -glucopyranoside (methyl α-nigeroside) was studied by X-ray crystallography. The crystal data are a 6.591 (2), b 13.243 (4), and c 9.446 (2) A, β 108.0° (1), space group P2 1 , Z 2. The structure, solved by direct methods, was refined to an R final value of 0.04. A hydrogen bond links the two d -glucopyranose rings of the same molecule. The orientation at C-1′O-3C-3 has been compared with that of disaccharides having an α- d -(1→x)-linkage. The valence angle C-1′OC-x varies to some extent in relation with the steric interaction of the bridge O-3. The glycosidic torsion angles are both influenced by the exoanomeric effect and the existence of an intramolecular hydrogen bond between the two rings. The latter disturbs the exoanomeric effect and modifies the torsion and pseudotorsion angles.