Hydrogenation to Succinic Acid

Catalytic hydrogenation of the olefinic bond in MA yields succinic anhydride. The same reaction can be achieved on any MA derivative. Succinic 

1 and anhydride (SA) 2 are commercially made this way/ A number hydrogenation catalysts can be successfully employed for this 

Allen et al have shown that the disodium salt of maleic acid can be reduced with Raney nickel at 100°C and 2 500 psi. The yield of succinic acid after acidification is near quantitative. Among other catalysts, platinum metals could be equally effective in bringing about the hydrogenation under milder 

Electrolytic reduction of maleic derivatives can also be used to produce the corresponding succinic derivatives. Takahashi and Elving have reported polarographic reductions of MA, maleate, and fumarate esters, and Elving and Teitelbaum have described the effect of pH on the polarographic reduction in protic solvents. Ruiz and Avila have also examined these pH effects on maleic and fumaric acids recently. 

In their study of maleic acid and fumaric acid, Takahashi and Elving reported that the two showed identical behavior in pyridine solution. Since extremely dilute solutions are employed, it may be expected that actually maleic acid completely isomerized to fumaric acid before the measurement, since pyridine is a known catalyst for the process.Isolation or spectral 

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Colourless prisms m.p. 130 C. Manufactured by treating maleic anhydride with water. It is converted to the anhydride by heating at By prolonged heating at 150 "C or by heating with water under pressure at 200 C, it is converted to the isomeric (trans) fumaric acid. Reduced by hydrogen to succinic acid. Oxidized by alkaline solutions of potassium permanganate to mesotartaric acid. When heated with solutions of sodium hydroxide at 100 C, sodium( )-malate is formed. Used in the preparation of ( )-malic acid and in some polymer formulations. 

Maleic and fumaric acids can be catalytically hydrogenated to succinic acid with ruthenium(II) chloride in aqueous solution (64). 

Detailed studies of 1 1 complex formation between and maleic and fumaric acids, which precedes reduction to succinic acid, cis-trans isomerisation and exchange of the double bond hydrogens, are relevant to the complex kinetics (A = substrate)... 

The simplest unsaturated dicarboxylic acids are maleic acid and fumaric acid, both of which are cheap, commercially available, materials. They are geometric isomers maleic acid is the (Z) isomer (19), and fumaric acid is the (E) isomer (20). Maleic acid forms an internal anhydride, maleic anhydride (21), which is widely used to form adducts with conjugated dienes (the Diels-Alder reaction, Section 7.6). The formation of the anhydride from maleic acid and the conversion of maleic acid into fumaric acid are described in Expt 5.218. The hydrogenation of maleic acid to succinic acid is of value as a means of evaluating the activity of a catalyst for use in hydrogenations at atmospheric pressure the experimental procedure is given in Section 2.17.1, p. 87. 

Succinic acid has a diverse range of applications in the synthesis of specialty chemicals used in agriculture, foods, medicine, textiles, plating, and waste-gas scrubbing (Winstrom, 1978). Currently, succinic acid is produced via the hydrogenation of maleic anhydride to succinic anhydride and hydration to succinic acid (Winstrom, 1978 Zeikus et al., 1995). The thermophylic anaerobic bacteria Clostridium thermosuccinogenes can convert inulin to succinate and acetate as major... 

The reverse of these reactions viz., the conversion of maleic and fumaric acids, by the addition of hydrogen bromide, into mono-brom succinic acid by the addition of two bromine atoms, into di-brom succinic acid and also by the addition of two hydrogen atoms, into succinic acid itself all show these same relations of maleic and fumaric acids to succinic acid and its bromine substitution products and establish the constitution of these isomeric di-basic unsaturated acids as given. The two acids may also be prepared from malic acid which is, in fact, the chief method by which they are prepared. This reaction will be considered later when malic acid itself is studied. 

Succinic acid is currently manufactured by the hydrogenation of maleic anhydride to succinic anhydride, followed by hydration to succinic acid. A fermentation process for succinic acid production is desirable because in such processes, renewable resources such as starchy crops and other agricultural products can be used as feedstock for the biological production of succinic acid. It addition, a high purity product, which is required as raw material for polymer manufacture, can be obtained. 

Early experiments concerned the enzymatic hydrogenation of fumaric acid to succinic acid, catalyzed by either yeast 24,55 or enzyme extracts from yeast cells56. Much later, strains of Escherichia coli, Aerobacter aerogenes and Aerobacter cloacae were shown to have the same ability 57,58. An interesting mixed culture fermentation has been developed, where the fungus Rhizopus chinensis produces fumaric acid from glucose and a selected E. coli converts the previously formed fumaric acid into succinic acid58. 

The second step is the catalytic hydrogenation of maleic acid to tetrahydrofuran. Maleic acid is quickly reduced to succinic acid, which, in turn, is reduced to 7-butyrolactone. The 7-butyrolactone is further reduced to either 1,4 butanediol or directly to tetrahydrofuran (THF). The final reaction... 

Chloro complexes of ruthenium(II) were found to hydrogenate maleic and fumaric adds to succinic acid slowly at 60-80 °C and normal pressure of hydrogen. Non-activated alkenes lead to the production of ruthenium metal. The structures of the species involved are unknown. The mechanism involves coordination of the alkene followed by heterolytic cleavage of hydrogen, giving a ruthenium(II) hydride as the second step. ... 

Processes based on mierobial fermentation are currently regarded as alternatives having the most potential in eonverting hemicelluloses into biofuels and chemicals such as ethanol, butanol, hydrogen, and succinic acid due to the advantages of low cost and environmental friendliness. Recent studies on biofuels and chemicals from hemicellulosic fermentation are shown in Table 7.2. 

Pathway V is based on the conversion of pyruvate (or) phosphoenol pyruvate to succinic acid via propionate as the intermediate. The dehydrogenation of propionyl-CoA removes two hydrogens and results in the formation of acryloyl CoA, which is hydrogenated to form 3- hydroxyl propionyl-CoA followed by hydrolysis to yield 3-HP (Jiang et al., 2009). There is no net ATP generation (instead the ATP yield is -1) in this pathway as a result, pathway... 

Here then the distinction between substrates and co-enzymes can only be made in terms of the quantities involved. These enz)une systems oxidatively decarboxylate a large amount of 2-oxoglutaric acid to succinic acid. The small amount of co-enzyme A acts over and over again and the small amount of co-enz)rme I (NAD) is constantly being re-oxidised by another set of enzymes and so acts over and over again to remove hydrogen from the 2-oxogIutarate. 

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