4,6-O-Benzylidene-d-glucopyranose and its sodium salt: new data on their preparation and properties

An improved method for the preparation of 4,6-O-benzylidene-d-glucopyranose (BG), and new or corrected data on its 1H and 13C NMR spectra, specific rotations, and tautomeric equilibria, and on those of its anomeric sodium salt (BGNa), are reported. Evidence is presented in favour of the hypothesis that crystalline BGNa exists entirely in its β-anomeric form and that it can be useful in the access to β-glucosides in reactions with strong electrophiles under strictly heterogeneous conditions.