Crystal and molecular structure of methyl 4-O-methyl-beta-D-ribo-hex-3-ulopyranoside

Carbohydr Res. 2004 Mar 15;339(4):795-9. doi: 10.1016/j.carres.2004.01.006.

Abstract

Methyl 4-O-methyl-beta-D-ribo-hex-3-ulopyranoside (2), a model compound for partially oxidized anhydroglucose units in cellulose, was crystallized from CHCl(3)/n-hexane by vapor diffusion to give colorless plates. Crystal structure determination revealed the monoclinic space group P2(1) with Z = 2C(8)H(14)O(6) and unit cell parameters of a = 8.404(2), b = 4.5716(10), c = 13.916(3)A, and beta = 107.467(4) degrees. The structure was solved by direct methods and refined to R = 0.0476 for 1655 reflections and 135 parameters. The hexulopyranoside occurs in a distorted chair conformation. Both hydroxyls are involved in hydrogen bonding and form zigzag bond chains along the b-axis. One of the two hydrogen bonds is bifurcated. The solid-state (13)C NMR spectrum of exhibits eight carbon resonances, with well-separated signals for the two methoxyls (1-OMe: 55.72 ppm, 4-OMe: 61.25 ppm) and a keto resonance with relatively large downfield shift (206.90 ppm). Differences in the C-4 and the methoxyls' chemical shifts in the solid and liquid states were found.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Cellulose / chemistry
  • Crystallization
  • Crystallography, X-Ray
  • Glucosides / chemistry*
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Sequence Data

Substances

  • Glucosides
  • methyl 4-O-methylhex-3-ulopyranoside
  • Cellulose