Phenylosazones osones

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... 

It has recently been reported21 that a mixed osazone of 3,4-di-O-methyl-D-glucose can be converted, by treatment with p-nitrobenzaldehyde, into an osone which reacts with phenylhydrazine to give 3,4-di-O-methyl-D-glucose phenylosazone. Von Lebedev29 claimed to have obtained D-glu-cosone 6-phosphate, isolated as an amorphous lead salt, by the action of hydrochloric acid on the phenylosazone prepared from D-fructose 6-phosphate. 

The tetrosones have not been prepared. Fischer2 observed that erythrose phenylosazone is relatively resistant to concentrated hydrochloric acid on warming, some decomposition took place, but osone was not formed. 

The benzaldehyde method has advantages, however, where high purity of the osone is desirable.98 When the reagent is employed, the purity of the osazone is of prime importance,90 and recrystallization from absolute ethanol may be usefully carried out for the xylose phenylosazones104 as well as for the arabinose phenylosazones.183... 

LaForge and Hudson194 prepared an osone from the phenylosazone obtained from sedoheptulose (D-aZ(ro-heptulose). The osone reduced Fehling solution strongly, formed the original osazone with phenylhydrazine, and gave a crystalline derivative with o-phenylenediamine. 

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... 

McDonald and Jackson was the phenylosazone, m. p. 183-184°, which agrees well with m.p. 184-187° for the phenylosazone made from 6-methyl-D-glucose.148 An alternative synthesis of 6-methyl-D-fructose is described by Hartley and Linnell.144 They converted 6-methyl-D-glucose to 6-methyl-D-fructose through the phenylosazone and osone. Their compound was a dark brown sirup, [< ]d +17.15° in water, which gave a phenylosazone, m. p. 184°, identical (mixed m. p.) with that obtained from 6-methyl-D-glucose. 

D-fructose were removed by alcoholic fermentation and the remaining sugars, L-gulose and L-sorbose, were converted into the phenylosazone that is common to these two hexoses. Although the presence of both L-sorbose and L-gulose is altogether probable, the isolation of the so-called sorbose phenylosazone is evidence only that at least one of these unfer-mentable hexoses, or indeed sorbose (gulose) osone, was present. 

From L-allulose Steiger " prepared the phenylosazone (L-allose phenyl-osazone), which was hydrolyzed to L-allosone (LXIV) by means of benzaldehyde. The addition of hydrocyanic acid to the osone, followed by saponification with hydrochloric acid, then yielded crystalline l-alloascorbic acid (LXV), of m. p. 177° (decomp.) and - -29.3° in... 

Whereas phenylhydrazine reacts with an osone to form a phenylosazone, 1,1-diphenylhydrazine reacts selectively with the aldehydic group to give a crystalline osone diphenylhydrazone ... 

The oxidation of aldose phenylosazones to aldos-2-uloses (osones) and the g.l.c. separation of the TMS ethers of the products have been examined in the cases of the D-f/ reo-pentose, D-arabino-, D-lyxo-, L-xy/o-hexose compounds, and two disaccharide derivatives. A new approach to the synthesis of ketonic carbohydrate derivatives involves the treatment of amino-compounds with sterically hindered quinones to prepare imines which rearrange as shown in Scheme 1 to give products which undergo hydrolysis to ketones. The method gave the 2- and 3-ulosides, respectively, when applied to methyl 2-amino-2-deoxy-a- and 3-D-glucopyranoside and methyl 3-amino-3-deoxy-j3-D-allo-furanoside. ... 

Keto-L-arabonic acid, prepared from the osone, loses carbon dioxide similarly, but the final product is not furfural but L-erythrose, isolated as the phenylosazone or as calcium L-erythronate after bromine oxidation ISl),... 

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