title: Synthesis and n.m.r.-spectral analysis of unenriched and [1-13C]-enriched 5-deoxypentoses and 5-O-methylpentoses.
abstract: Chemical methods are described for preparing unenriched and [1-13C]-enriched 5-deoxy- and 5-O-methyl-pentoses in the D or L configuration. The 1H-n.m.r. spectra of these compounds have been interpreted, and the 13C-n.m.r. spectra assigned with the aid of 2-D 13C-1H chemical-shift correlation spectroscopy. Tautomeric forms (furanoses, hydrate, and aldehyde) in solution in 2H2O have been quantified with the aid of [1-13C]-enriched derivatives. Spectra of 5-deoxypentoses, 5-O-methylpentoses, and methyl pentofuranosides have been compared, in order to assess the effect of 5-C-deoxygenation and 5-O-methylation on chemical shifts and coupling constants (1H-1H, 13C-1H, and 13C-13C) and on the pentofuranose conformations.
mesh_terms: D002236:Carbohydrate Conformation; D002247:Carbon Isotopes; D007202:Indicators and Reagents; D007536:Isomerism; D007553:Isotope Labeling / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D010429:Pentoses / Q000138:chemical synthesis*
chemical_list: D002247:Carbon Isotopes; D007202:Indicators and Reagents; D010429:Pentoses