text: Direct carbon-proton coupling constants are used to study the anomeric configuration of a sugar.
  Vicinal proton-proton coupling constants are used to study stereo orientation of protons relatively to the other protons within a sugar ring, thus identifying a monosaccharide.
  Vicinal heteronuclear H-C-O-C coupling constants are used to study torsional angles along glycosidic bond between sugars or along exocyclic fragments, thus revealing a molecular conformation.
  Sugar rings are relatively rigid molecular fragments, thus vicinal proton-proton couplings are characteristic:
  *Equatorial to axial: 1–4 Hz
  *Equatorial to equatorial: 0–2 Hz
  *Axial to axial non-anomeric: 9–11 Hz
  *Axial to axial anomeric: 7–9 Hz
  *Axial to exocyclic hydroxymethyl: 5 Hz, 2 Hz
  *Geminal between hydroxymethyl protons: 12 Hz