Vibrational Raman optical activity of ketose monosaccharides

The vibrational Raman optical activity (ROA) spectra of the four ketose sugars d-fructose, l-sorbose, d-tagatose and d-psicose in aqueous solution, which have been measured in backscattering in the range ≈250–1500 cm−1, are reported. These results are combined with those from a previous ROA study of aldose and pentose sugars in an attempt to establish new vibrational assignments and to verify old ones. The high information content of these spectra provides a new perspective on all the central features of monosaccharide stereochemistry including dominant anomeric configuration, ring conformation, exocyclic CH2OH group conformation and relative disposition of the hydroxyl groups around the ring