Hydrogenolysis of the isomeric 1,2:4,6-di-O-benzylidene-α-d-glucopyranose derivatives with the LiAlH4AlCl3 reagent

Both isomers of 1,2:4,6-di-O-benzylidene-α-d-glucopyranose (and their 3-O-acetyl and 3-O-benzyl derivatives) have been prepared and their ¹H- and ¹³C-n.m.r. spectra assigned. The mode of hydrogenolysis of the dioxolane ring in these isomers by the LiAlH₄AlCl₃ reagent is determined by the configuration at the acetal carbon and is independent of the electronic character of the two oxygen atoms.