The bioactive amino monosaccharide D-glucosamine has been generated in gas phase via laser ablation of
D-glucosamine hydrochloride. Three cyclic α-
4C1
pyranose forms have been identified using Fourier
transform microwave techniques. Stereoelectronic hyperconjugative forces – essentially linked with the
anomeric or gauche effect – and cooperative OH…O, OH…N and NH…O chains, extended along the entire
molecule, are found to be the main factors driving the conformational behavior. The orientation of the
NH2
group within each conformer has been determined by the values of the nuclear quadrupole constants.
The results have been compared with those recently obtained for the archetypical D-glucose.
