STRUCTURE OF BETA-GLUCOCHLORALOSE¹

Abstract

Two crystalline chloral derivatives of glucose were reported by Heffter2 in 1889 but were not named. More detailed studies of the chloral derivatives of the various carbohydrates have been made by Hanriot3 and his associates, by Meunier,4 by Petit and Polonowski,3 and by Pictet and Reichel.6 The most recent formula for the j3-glucochloralose is that of Pictet and Reichel (Formula III). Most of the standard handbooks give the older formula of Hanriot (Formula I) or of Polonowski (Formula II). The evidence regarding the structure of ß-glucochloralose is conflicting. The absence of reducing properties, the failure to combine with hydroxylamine and phenylhydrazine and the resistance of the compound to hydrogenation all indicate that the free aldehyde groups of both the glucose and the chloral have been modified in their union. The formation of 1 This compound is also called "Parachloralose."

The Structural Significance of Glyceraldehyde and Glycollic Aldehyde in Polysaccharide Degradations and Their Recovery and Identification as the Reduced Analogues

“…The syrupy product which presumably already contained some monoacetone-galactose v+as dissolved in ethyl acetate containing concentrated nitric acid (16) Bromine Oxidation T o the above mixture was added bromine a t 1-hour intervals, in the presence of barium carbonate, to transform D-glyceraldehyde t o the corresponding carboxylic acid. The completion of this reaction was assumed from the change in the specific rotation to that approximating D-glyceric acid (barium salt), [a]n25 21.3" (c, 1.5 in water).…”

“…This co~npound was prepared according to the general procedure described by Isbell (16). A quantity (3.2 g) of the 1,2-orthoacetate was obtained by alkaline deacetylation of 3,4,6-triacetyl-D-mannose 1,2-orthoacetate.…”