Structure of saccharide osazones
For the arylosazones of saccharides, the evidence of X-ray crystallography, n.m.r., i.r., and u.v. spectroscopy, and chemical reactivity, provide strong support for a structure (1) having an acyclic carbohydrate chain and a bishydrazone system stabilized by a hydrogen bond between the imino-proton of the C-2 hydrazone residue and the nitrogen atom attached to C-1. This structure is adopted in the solid state and is also the principal form in solution. A structure (2), having the sugar residue in a ring form, cannot be reconciled with the observed facts for the saccharide osazones, whether in the solid state or in solution.