Glucosone phenylosazone

D-Glucosone (XII), prepared from D-glucose phenylosazone (XI) by the action of concentrated hydrochloric acid, is treated in aqueous solution with potassium cyanide. The imino-D-glucoascorbic acid (XIV) which readily separates shows many of the properties of ascorbic acid. Thus it shows a strong selective absorption band in the ultra-... 

Although no D-glucosone was obtained by the action of formaldehyde on D-glucose phenylosazone,19 Briill28 successfully decomposed the osazone with an excess of pyruvic acid. An improved procedure has been described, and the decomposition of D-glucose phenylosazone with glyoxal has been reported.18... 

Partially methylated derivatives of D-glucosone have been prepared by decomposition of the corresponding partially methylated phenylosazones with p-nitrobenzaldehyde osones have been obtained from 5-0-methyl-D-glucose phenylosazone and from 3,4,5-tri-O-methyl-D-glucose phenylosazone in this way.22 Although 6-0-methyl-D-glucose phenylosazone is not altered by heating with benzaldehyde or piperonal in aqueous ethanolic... 

Bayne, Fewster and Mitchell16 prepared VII by the method of Stacey and Turton, and recorded physical properties closely agreeing with those reported by Maurer.66 The compound was clearly related to D-glucosone, prepared from D-glucose phenylosazone and by direct oxidation, since, on treatment with dry acetone containing concentrated sulfuric acid, it gave crystalline tri-0-isopropylidene-(2-hydroxy-D-arabmo-hexose). 7... 

This osone was first prepared from cellobiose phenylosazone by the benzaldehyde method196 on hydrolysis by emulsin it gave D-glucosone and D-glucose. 

Lactosone was first prepared by the hydrochloric acid decomposition of the phenylosazone,1 although it had been noted that, in acid solutions, lactose phenylosazone forms an anhydride.197 Since its discovery,17 the benzaldehyde method has usually been employed,6-10-28 because it avoids the risks of osone hydrolysis and of alteration to the osazone. Lactosone is hydrolyzed by hot, dilute, mineral acid to D-glucosone and D-galactose.1-6 It reacts with cyanide to form an analog of iminoascorbic acid which, on acid treatment, is converted into a mixture of D-glucoascorbic acid and D-galactose.10... 

Because the phenylosazone and tetrahydroxybutylquinoxaline derivatives of D-glucosone have been isolated from 1-deoxy-l-p-toluidino-D-fruc-tose in high yields, 1,2-enolization of the aminodeoxyketose must predominate over 2,3-enolization. No proof for 2,3-enolization is known at present. The sequence of reactions (in alkali) which lead from the aminodeoxyketose (XVI) through the 1,2-enediol (XVIII) to the glycosone (XIX) are thought to be as follows ... 

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