M. Anteunis, J. Beeumen, A. Bruyn
Sep 2, 2010
Citations
0
Influential Citations
5
Citations
Journal
Bulletin des Sociétés Chimiques Belges
Abstract
The chemical structure of the glucoside-ulose O-β-D-xylo-hexopyranosyl-3-ulose-(1 4)-D-glucopyranoside (trivial name: 3-keto-lactose) is studied by nuclear magnetic resonance in deuterated dimethyl sulfoxide. The technique of multiple irradiation allows the identification of most of the signals in the spectrum (fig. 2). informative data are also obtained from the spectrum of β-D-galactopyranose (2) and methyl O-β-D-ribohexopyranoside-3-ulose (3) (trivial name: methyl β-3-keto-D-glucopyranoside). The lack of a free carbonyl function in 3-keto-lactose is due to the presence of the hemiacetal which is formed on crystallizing the compound from methanol. The hydroxyl group at the anomeric carbon atom has the β-configuration (1). It is suggested that this ketosugar prevails dominantly as the hydrate when it is prepared from aqueous solutions.