Phenylosazones conversion

Methylation was accomplished by direct conversion of the acetyl derivative as previously described. The final product contained 45% OCHs. Molecular weight determinations in benzene gave values representing 18 to 19 D-fructose residues. Hydrolytic products of the methyl derivative were separated by conversion to benzoyl derivatives. The trimethylfructose was identified as 3,4,6-trimethyl-D-fructofuranose by its phenylosazone. The authors conclude that the ratios 1 3 1 exist among the di-, tri-, and tetramethyl-D -fructoses produced by the hydrolysis. 

The non-aqueous oxidation of various ketones and aldehydes to hydroxyaldehydes and hydroxy ketones has been carried out in two steps the first step is a bromination and the second a hydrolysis, or replacement of the bromine atoms by hydroxyl groups. Fischer and Landsteiner " brominated acetal in the presence of calcium carbonate (reaction 20). The bromoaldehyde Avas then treated with cold barium hydroxide solution (reaction 21) the resulting glycolic aldehyde was identified by conversion to glyoxal phenylosazone (reaction 22) and by the formation of calcium glycolate, after oxidation with bromine (reaction 23). 

The conversion of calcium o-altronate to n-altrose follows the standard procedure of Fischer, which consists in liberating the aldonic acid, heating it to effect lactonization, and reducing the sirupy lactone with sodium amalgam. Levene and Jacobs thus prepared n-altrose as a sirup, but did not record its rotation. It formed a crystalline phenylosazone, which is common to both n-altrose and n-allose, and a characteristic benzylphenylhydrazone. Pertinent data on these substances, and on ... 

Bayne observed that lactosazone is readily converted into anhydro-lactosazone in hot alcohol, and he recommended extraction with hot water for purification of the osazone. The water-insoluble anhydrolactosazone was identified as 3,6-anhydro-4-0-/3-D-galactopyranosyl-D-rf6o-hexose phenylosazone (39 R = D-galactopyranosyl) by conversion with aqueous copper sulfate to its phenylosotriazole, which was then hydrolyzed to give D-galactose and the phenylosotriazole of 3,6-anhydro-D-rf6o-hexose. 

The glycosulos-3-enes are theoretically derived from a 3-deoxyglycosulose by the loss of one molecule of water per molecule. A compound of this type, (32), was first isolated as the phenylosazone by Wolfrom, Wallace, and Metcalf, and was shown to be an intermediate in the conversion of 1-deoxy-tetra-O-methyl-D-orobtno-hexopyranos-l-ene (31) (tetra-O-methyl-n-glucoseen-1,2) to 5-(methoxymethyl)-2-furaldehyde (33). The evidence... 

Because of the chelated structure of sugar osazones, the osazone formazan 181, obtained by coupling diazotized [14C]aniline to a saccharide phenylosazone (180) loses 42%) of the label (as aniline) upon conversion to an osolriazole (182), whereas the formazan of an unchelated osazone, such as pyruvaldehyde osazone loses exactly half of the radioactivity as aniline during osolriazole formation (Scheme 40).168... 

Formation of Pyrazoles from Bis(hydrazones).—Mesoxaldehyde bis(phenylhydrazone) (193), obtained by periodate oxidation of saccharide osazones (192) is readily cyclized in the presence of acids to give l-phenyl-4-phenylazo-pyrazole (195).162 365 Hexulose phenylosazones (192) are also disproportionaled in the presence of acidic salts of carbonyl reagents, such as hydroxylamine hydrochloride, to give l-phenyl-4-phenylazo-pyrazolin-5-one (196). The reaction probably proceeds via mesoxalic acid 1,2-bis(phenylhydrazone) (194).365 The hydroxalkyl derivatives of 196 are produced from dehydroascorbic acid bis(phenylhydrazone) by treatment with base to open the lactone ring and permit the conversion of 197 to 199.351,366 Another type of pyrazole that is formed by dehydrating osazones with acetic anhydride is discussed later under anhydroosazones (see Schemes 45,53). 

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