Dihydroxyfumaric acid

Fenton s reagent. To a solution of tartaric acid or a tartrate add 1 drop of freshly prepared ferrous sulphate solution, i drop of hydrogen peroxide solution and then excess of NaOH solution an intense violet coloration is produced, due to the ferric salt of dihydroxyfumaric acid, HOOC C(OH) C(OH)COOH. 

This reaction sequence is a general one for ene-diols. For example, in the same conditions, dihydroxyfumaric acid is oxidized by two moles of periodate, first to a diketone and then to two moles of oxalic acid (25,56). 

Biosyntheses of hexuronic acids and L-ascorbic acid in plants and animals are closely related. Hexuronic acids, L-ascorbic acid, and L-tartaric acid (a possible precursor of dihydroxyfumaric acid) commonly occur together in plants. If a rat is given chloretone (an antispasmodic), both L-ascorbic acid and D-glucuronic acid are excreted in increased quantity.244 Unlike humans, rats can synthesize their own vitamin C, and are therefore independent of outside sources. Here, D-glucose and D-galactose can be utilized, but not D-mannose. 

Dehydrogenation HO COOH Q O COOH 2 jr 2 T +2H20 HOOC OH HOOC 0 Dihydroxyfumaric acid HRP... 

Selective hydroxylation of some aromatic compounds can be achieved using HRP C in the presence of oxygen and dihydroxyfumaric acid (270). This process afforded l-DOPA from L-tyrosine, D-(-)-3,4-dihydroxy-phenylglycine from D-(—)-4-hydroxyphenylglycine, and L-epinephrine (adrenalin) from L-(-)-phenylephrine in yields of up to 70%. 

Dihydroxymaleic acid (dihydroxyfumaric acid hydrate) [133-38-0] M 148.1, m 155 (dec). Crystd from water. 

Pasta P, Carrea G, Monzani E, Gaggero N, Colonna S (1999) Chloroperoxidase-Catalyzed Enantioselective Oxidation of Methyl Phenyl Sulfide with Dihydroxyfumaric Acid/Oxygen or Ascorbic Acid/Oxygen as Oxidants. Biotechnol Bioeng 62 489... 

Fig. 6.5 FIRP catalyzed hydroxylation of L-tyrosine to L-Dopa in the presence of dihydroxyfumaric acid...

The nuclear hydroxylation of aromatics can be catalyzed by horseradish peroxidase, and with suitably activated substrates synthetically useful yields can be obtained.The reactions are usually carried out at 0 C in the presence of dihydroxyfumaric acid cofactor and a source of oxygen. Thus l-DOPA (102) has been prepared using this system. ... 

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. 

An interesting application of this method is a convenient synthesis of the parent oxazole.124 186 It is prepared by oxidizing tartaric acid with hydrogen peroxide to dihydroxyfumaric acid (55), the methyl or ethyl ester of which is condensed with formamide in the presence of hydrogen chloride to give 4,5-dialkoxycarbonyloxazole (56, R = Me or Et), which is saponified with aqueous barium hydroxide or alcoholic sodium hydroxide. The anhydrous salt is then decarboxylated to oxazole, without isolation of the comparatively unstable 4,5-oxazoledicarboxylic acid, in 55-70% yield. 

The third type of oxygen transfer reactions is the hydroxylation of aromatic compounds [88,89], Selective hydroxylations of aromatic compounds are very difficult in preparative organic chemistry because they are laborious, time-consuming and, most important, inefficient. However, hydroxylations of some aromatic compounds may be performed by class III plant peroxidases at the expense of molecular oxygen and in the presence of dihydroxyfumaric acid (XI) as propagator (Scheme VII). 

A stirred mixture of dihydroxyfumaric acid, Mg-sulfate, and methanol treated 4.5 hrs. at 0-5 with anhydrous HCl, and stored 3 days at room temp. -> dimethyl dihydroxyfumarate. Y 93.2% 45% without MgS04. E. E. Jaffe and H. Matrick, J. Org. Chem. 33, 4004 (1968). 

If the reaction is incompatible with a peroxo species, molecular oxygen in presence of a chemical reductant (such as ascorbic or dihydroxyfumaric acid) may be used as oxidant [1353, 1354]. 

Dry urea added to a soln. of anhydrous dihydroxyfumaric acid in n-butanol, the resulting suspension cooled to 0°, satd. with dry HGl, more n-butanol added until a soln. results, and stored 3 days at room temp. di-n-butyl 2-imidazo-lone-4,5-dicarboxylate. Y 72%. F. e. s. P. H. Laursen and B. E. Christensen, J. Org. Chem. 27, 2500 (1962) method s. H. J. H. Fenton and W. A. R. Wilks, Soc. m, 1570 (1912). 

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