Mesaconic acid

Colourless liquid b. p. 213—214° (ordinary pressuie). To convert the anhydiide into citraconic acid tlae calculated quantity of water is added (i mol. acid i mol. water), and the mi-vture well stirred. The whole solidifies, on standing, to a mass of colourless crystals of citraconic acid, whicb arc dried on a porous plate m. p. 84—86°. 

CONIC Acid.—To a saturated solution of citraconic acid in ether (4 parts citraconic acid require about 5 parts of anhydrous ether), about i part of chloroform is added, and a few drops of a moderately strong solution of bromine in chloroforna-The mixture is placed in strong sunlight, when mesaconic acid, which is insoluble in ether and chloroform, begins at once to deposit on the side of the vessel nearest the light. Drops of bromine are added from time to time until no further precipitation occurs. The pasty mass is then filtered, washed with ethei, and dried on a porous plate. Yield 73 per cent, of the citraconic acid m. p. 203°. See Appejidix, p. 265. 

A mixture of 100 g. (0.88 mole) of citraconic anhydride (p. 28) (Note 1), 100 cc. of water, and 150 cc. of dilute nitric acid (1 part of concentrated nitric acid to 4 parts of water by volume) is evaporated in a 500-cc. Erlenmeyer flask until the appearance of red fumes (Note 2). The solution is cooled and the mesaconic acid is collected on a filter. The mother liquor is evaporated to 150 cc., cooled, and the crystalline solid which separates is collected on a filter. Further concentration of the mother liquor to 50 cc. yields more product (Note 3). The entire product is recrystallized from roo cc. of water. The yield of product melting at 203-205° is 50-60 g. (43-52 per cent of the theoretical amount). 

It is necessary to carry the evaporation to the point where red fumes appear in order for the rearrangement to take place. The volume is usually about 250 cc. 

The concentration of the mother liquor must be carried out in steps in order to obtain an efficient separation of mesaconic acid. 

Mesaconic acid has been prepared by heating citraconic acid with dilute nitric acid, with hydriodic acid,2 or with concentrated sodium hydroxide solution 3 by heating a concentrated water solution of itaconic or citraconic acid at 180-200° 4 by treating citradibromopyrotartaric acid and mesodibromopyrotartaric acid with potassium iodide and copper at 1500 5 and by heating citraconic anhydride with nitric acid.6 

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Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Mesaconic acid (methylfumaric acid) [498-24-8] M 130.1, m 204-205°, pK 4.82. Crystd from water or EtOH [Katakis et al. J Chem Soc, Dalton Trans 1491 79S6]. 

Karrer and Matter have confirmed the presence of succinic acid as recorded by Boehm, and of protoeatechuic acid as found by Wieland, Konz and Sonderhoff and have added thereto, mesaconic acid as a constituent of calabash curare. 

C. Itaconic Acid, Citraconic Acid, and Mesaconic Acid... 

GC separation of derivatized carboxylic acids, 46-52 bacterial fatty acids, 51-52 bile acids, 50-51 C6-C24 monocarboxylic acids and dicarboxylic acids, 51 cyano acids, 52 higher-boiling acids, 49 itaconic acid, citraconic acid, and mesaconic acid, 49... 

Mercaptoethanol reagent 380 Mercury cations 144,311 Mercury lamps 20, 22 ff emission lines 23, 24 -, high pressure 22 ff -, technical data 23 Mercury(I) nitrate reagent 337 Mercury(II) salt reagent 340 Mesaconic acid 61 Mesoporphyrin 101, 102 Metal cations 310—312,398 Metal complexes 248, 398 Methanol, dipole moment 97 Methine dyestuffs 360 4-Methoxyaniline see Anisidine 4-Methoxybenzaldehyde see Anisaldehyde Methoxybenzaldehyde derivatives 72 Methoxycinnamic acid 277... 

Citric acid yields itaconic, citraconic, and mesaconic acids during coffee roasting.3... 

On similar reasonings the configuration of citraconic acid is cis because it forms the anhydride while its isomer mesaconic acid is trans. 

S. Except for oxido-reductases, transferases, and hydrolases, most ligases (enzymes that catalyze bond formation) are entirely substrate specific. Thus, fumarate hydratase (or fumarase) reversibly and stereospecifically adds water to fumaric acid to produce (S)-( — )-malic acid only (8) (Figure 1), and another enzyme, mesaconase, adds water to mesaconic acid to form (+ )-citramalic acid (9) (Figure 2). Although no extensive studies are available, it appears that neither fumarase nor mesaconase will add water stereospecifically to any other a,(3-unsaturated acid. 

The peak at 17.34 min is 50 pg ml mesaconic acid which was added as a possible internal standard, but it proved unsuitable because of an unknown peak eluting at 16.78 minutes seen when analysing silage juice without added internal standard oxalic acid suffered from the same problem. We still need a suitable internal standard for this column, thus further use was suspended. Other failed compounds included adipic acid, fumaric acid, D-glucuronic acid, glutaric acid, glycolic acid, 3-hydroxybutanone, itaconic acid, malic acid, maleic acid, malonic acid, pimelic acid and succinic acid. 

Preparation 423.—Mesaconic Acid [tians-3-Carboxy-2-luten add], CH,... 

Cis- and /ra s-isomers sometimes differ in their half-wave potentials, so that the individual isomers can be distinguished and in some instances their mixtures analysed. Differences in the values for cis- and trans-isomers have been reported for azocompounds (115, 116) (but cf. (117 bis 119)), oximes (120), unsaturated carbonyl compounds (121—123), unsaturated hydrocarbons (124), etc. In some cases, the heights of the waves of isomers at a given pH, or the pK values differ, so that mixtures of isomers can be analysed. This is possible for mixtures of fumaric and maleic acids (125—128), citraconic and mesaconic acids (125), etc. 

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