Hydrazones of sugars

Hexuronic acids, methyl ethers of, 9, 131-148 Hibbert, Harold, obituary of, 16, 1-11 Hudson, Claude Silbert, obituary of, 9, xiii-xviii Hyaluronic acid, biosynthesis of, 12, 299-319 Hydrazones, of sugars, 3, 23-44 Hydrocolloids,... 

The hydrazones of sugars are capable of existing in various cyclic forms, whose presence is apparent from their nuclear magnetic resonance (NMR) spectra and from the complex mutarotation curves they exhibit110,111117118 (which seldom follow first-order kinetics). The principal structures encountered in saccharide hydrazones are the acyclic, Schiff base-type true hydrazones and the cyclic hydrazino forms, namely glycopyranosyl- and gly-cofuranosylhydrazines. For example, three isomeric forms of D-glucose phenylhydrazone have been isolated.119 The Schiff base derivatives can be... 

Hyaluronic acid, biosynthesis of, 12, 299-319 Hydrazones, of sugars, 3, 23-44 Hydrocolloids,... 

The production of various hydrazones of sugars acetic acid solution has been described. ... 

Another spectrophotometric method measuring both simple and combined sugars was described in papers by Johnson and Sieburth [158] and Burney and Sieburth [159]. The basic method comprised reduction of sugars to alditols with sodium borohydride, and oxidation of the alditols to form free formaldehyde. The formaldehyde was then determined spectrophotometrically with 3-methyl-2-benzothiazolinone hydrazone hydrochloride. 

Although the characterization of Sugars and their derivatives as (substituted) hydrazones requires relatively mild conditions, an unexpected reaction was observed87 when 3,5-di- O-benzoyl-2-deoxy-D-erj/tAro-pentose (1)... 

Phenylhydrazinc, as hydrochloride solution plus sodium acetate, reacts with polyhydroxy aldehydes or ketones yielding osazones or diphenyl-hydrazones, yellow solids, of definite melting point and utilized in identification of sugars, e.g.. phenyl-d-glucosazone. CH OH (CHOH), C (NNHC6H5)CH (NNHCftH,) plus aniline C6H5NH plus NH,... 

Since the discovery of the reaction of phenylhydrazine with sugars to form osazones by Fischer,35 many investigations have utilized this reaction in the identification and separation of sugars, but the precise structures of osazones and their mode of formation are still in doubt.34 There is no doubt, however, that the initial reaction involves the formation of a hydrazone, which then reacts further to yield eventually a f)u-l,2-hydrazone or osazone. 

The incorporation of [2-14C]pyruvate and [l-14C]acetate into sugars 17 and 18 was investigated.27 Oxidation of the methyl glycosides of sugar 17 with periodate yielded acetaldehyde from the 1-hydroxyethyl branch. The acetaldehyde (2,4-dinitrophenyl)hydrazone was further oxidized by Kuhn-Roth oxidation to acetic acid, which was degraded by the Schmidt reaction to methylamine and carbon dioxide. Periodate oxidation of the methyl glycosides of sugar 18 produced acetic acid from the C-acetyl branch. The acetic acid was isolated, and purified as 1-acetamidonaphthalene. 

Dimethyl-l,3-dioxan-5-one SAMP/RAMP hydra-zones j were used as dihydroxyacetonephosphate equivalents in the synthesis of C2 symmetric ketones (eq 5), aza sugars with novel substitution patterns, or C5 to C9 deoxy sugars. SAMP hydrazones of 2-oxo esters represent novel phosphoenolpyruvate (PEP) equivalents. a,a-Disubstituted spiroacetals are accessible via the alkylation of ketone SAMP/RAMP hydrazones. ... 

A study of the Tables at the end of this review will reveal that a wide range of amines has been used to prepare compounds of the type under discussion. They include ammonia, and primary and secondary aliphatic, alicylic, and aromatic amines, as well as many heterocyclic amines. The methods used for preparing arylhydrazones of sugars (and the properties of these compounds) have many similarities with those for glycosylamines. These hydrazones have been surveyed by Percival. ... 

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