Equilibria between pyranoses and furanoses. IV. 1-Deoxyhexuloses and 3-hexuloses

Abstract

The equilibrium compositions of 1-deoxy-D-fructose, 1-deoxy-L-sorbose, 1-deoxy-L-psicose, D-threopentulose, D-arabino- and L-xylo-3-hexulose and coriose in aqueous solution have been determined by ¹³C N.M.R. spectroscopy. In all but the last case, considerable amounts of the acyclic keto form are present at equilibrium. The hydrated keto form was not detected; a model compound, l-deoxy- 3,4,5,6-tetra-O-methyl-D-fructose, was found not to be hydrated in aqueous solution.