Dihydroxytartaric acid

Rea.ctlons, When free (R-R, R -tartaric acid (4) is heated above its melting point, amorphous anhydrides are formed which, on boiling with water, regenerate the acid. Further heating causes simultaneous formation of pymvic acid, CH COCOOH pyrotartaric acid, HOOCCH2CH(CH2)COOH and, finally, a black, charred residue. In the presence of a ferrous salt and hydrogen peroxide, dihydroxymaleic acid [526-84-1] (7) is formed. Nitrating the acid yields a dinitro ester which, on hydrolysis, is converted to dihydroxytartaric acid [617 8-1] (8), which upon further oxidation yields tartronic acid [80-69-3] (9). 

Phenylethyl Alcohol Pyruvic Acid Oxalylacetic Acid Dihydroxytartaric Acid Dihydroxymaleio Add Acetonedicarboxylic Acid (ethyl ester) Muoonio Acid... 

The submitters employed dihydroxytartaric acid disodium salt hydrate purchased from Aldrich Chemical Company, Inc. 

Dihydroxytartaric acid, disodium salt hydrate Butanedioic acid, tetrahydroxy-, disodiura salt (9) (866-17-1)... 

This is the simplest member of the pyrazolone dyes which are prepared in two ways (a) from dihydroxytartaric acid and phenylhy-drazine (tartrazines), and (b) from phenylmethylpyrazolones by coupling with diazo compounds. The second method is simpler and has largely displaced the older, first method. The pyrazolone is prepared from a given phenylhydrazine (e.g., phenylhydrazinesulfonic acid, page 128) and acetoacetic ester, and coupled with diazotized aniline ... 

Some of the earliest kinetic studies on metal ion-promoted reactions were carried out on metal ion-promoted decarboxylations of j8-oxo acids. The literature on this topic up to about 1974 has been reviewed. Much of the work has centred on oxaloacetic acid (HO2CCOCH2CO2H = H20xac) and its derivatives, a,a-dimethyl oxaloacetic acid and fluorooxaloacetic acid. Studies have also been made with acetonedicarboxylic acid (3-oxoglutaric acid), " dihydroxyfumaric acid, dihydroxytartaric acid, acetosuccinic acid, oxalosuccinic acid and 2-oxalopropionic acid (Figure 6). The decarboxylation of )3-oxo acids is of considerable biological importance, and in a number of cases metalloenzymes are involved. Similarities in the enzymatic and chemical processes stimulated early interest in these reactions as models for the enzymatic systems. 

Quinoxaline-2,3-dicarboxylic acids are directly synthesized by condensation of an o-phenylenediamine with dihydroxytartaric acid (Scheme... 

The free acid HOOC CO CO COOH is unknown. The hydrated form (above formula), dihydroxytartaric acid or tetrahydroxysuccmic acid has m.p. 114-15° decomp. —> COg + tartronic acid. Aq. sol. of acid and salts decomp. on heating. Esters of the hydrated form are unknown. 

Test with the Na salt of dihydroxytartaric acid osazone ... 

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