Pyruvic acid hydrolysis

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. ... 

The sodium or potassium salt of 6-azauracil in aqueous ethanol, anhydrous ethanol, or ethylene glycol reacted with methyl iodide practically exclusively to give the 3-methyl derivative (63). In toluene the sodium, potassium, and mercuric salts produced no methylated derivatives whereas the silver salt also yielded the 3-methyl derivative, Similarly, the 3-methyl derivative was prepared from the mercuric salt of 6-azathymine, and its structure was established by hydrolysis to pyruvic acid 4-methylthiosemicarbazone. ... 

Only in the case of the pyruvic acid condensation product was it possible to isolate the corresponding ethyl ester under these conditions. This, on mild hydrolysis, reverted to 1-methyl-1,2,3,4-tetrahydro-j8-carbohne-1-carboxylic acid, identical with the starting material, which therefore had the assigned structure 26 (R = CH3) and was not the SchiflF s base 25 (R = CH3). Alkaline hydrolysis of the ester was accompanied by decarboxylation. ... 

Catalytic reduction of the nitrile 79 in the presence of semicarbazide affords initially the semicarbazone of 80. Hydrolysis-interchange, for example in the presence of pyruvic acid, gives the aldehyde 80. Condensation with the half ester of malonic acid leads to the acrylic ester 81 the double bond is then removed by means of catalytic reduction (82). Base catalyzed reaction of the... 

The pyruvic acid may also be linked to vicinal positions. When linked to 0-3 and 0-4 of a D-galactopyranosyl residue (40), the dioxolane ring becomes cw-fused. In the limited number of known examples, the absolute configuration at the acetalic carbon atom is (S), as in 40. There are some examples of tra -fused dioxolane rings, and these are more sensitive to hydrolysis with acid than the others. Thus, pyruvic acid is acetalically linked to 0-3 and 0-4 of an a-L-rhamnopyranosyl residue in the Klebsiella type 72 capsular polysaccharide, to 0-2 and 0-3 of an a-D-galactopyranosyl residue in the Streptococcus pneumoniae type 4 capsular polysaccharide, and to 0-2 and 0-3 of a S-D-glucopyranosyluronic acid residue in the Klebsiella K1 capsular polysaccharide. " In the extracellular polysaccharide from... 

A. Phosphoenolpyruvate.—The mechanisms of hydrolysis of phosphate esters of phosphoenol pyruvic acid (33) have been described in detail, and 0 studies confirm an earlier postulate that attack by water on the cyclic acyl phosphate (34) occurs at phosphorus and not at carbon. In the enolase reaction, the reversible interconversion of 2-phosphoglyceric acid(35)... 

Pyruvic acid is the simplest homologue of the a-keto acid, whose established procedures for synthesis are the dehydrative decarboxylation of tartaric acid and the hydrolysis of acetyl cyanide. On the other hand, vapor-phase contact oxidation of alkyl lactates to corresponding alkyl pyruvates using V2C - and MoOa-baseds mixed oxide catalysts has also been known [1-4]. Recently we found that pyruvic acid is obtained directly from a vapor-phase oxidative-dehydrogenation of lactic acid over iron phosphate catalysts with a P/Fe atomic ratio of 1.2 at a temperature around 230°C [5]. 

The following substrates were obtained from commercial sources, methyl pyruvate (1), methyl acetoacetate (2), methyl 4-oxopentanoate (1), and methyl 3-oxopentanoate ( ). Alkyl 5-oxohexanoates (4, 5 and 6) were prepared by condensation of methyl acetoacetate and methyl acrylate followed by acidic hydrolysis, decarboxylation, and esterification [8]. Methyl 3-oxo-4-methylpentanoate... 

Nef prepared acetol in several ways, the more important of which depended upon the reaction between bromoacetone and potassium or sodium formate or acetate, and the subsequent hydrolysis of the ester by methyl alcohol.1 2 Acetol is also formed, together with pyruvic acid, by the direct oxidation of acetone by Baeyer and Villiger s acetone-peroxide reagent.3... 

Pyrophosphates, diaryl, effect of cycloamyloses on hydrolysis of, 23 235 Pyrophyllite, idealized formula, 33 337 Pyruvic acid... 

Chemical/Physical. Slowly reacts with moisture at room temperature forming pyruvic acid (Frank and Demint, 1969 Kenaga, 1974), hydrochloric acid, and sodium chloride (Kenaga, 1974 Wolfe et al., 1990). The reported hydrolysis half-life of dalapon sodium salt at low concentrations (<1%) and temperatures less than 25 °C is several months (Kenaga, 1974). 

This is another exampie of substrate-level phosphorylation, but differs from the earlier example that involved hydrolysis of a mixed anhydride. Here, we have merely the hydrolysis of an ester, and thus a much lower release of energy. In fact, with 1,3-diphosphoglycerate, we specifically noted the difference in reactivity between the anhydride and ester groups. So how can this reaction lead to ATP synthesis The answer lies in the stability of the hydrolysis product, enolpyruvic acid. Once formed, this enol is rapidly isomerized to its keto tautomer, pyruvic acid, with the equilibrium heavily favouring the keto tautomer (see Section 10.1). The driving force for the substrate-level phosphorylation reaction is actually the position of equilibrium in the subsequent tautomerization. 

A synthesis of acetylalanine, from which alanine can be obtained by hydrolysis, was described in 1900 by de Jong. Pyruvic acid was neutralised with ammonium carbonate there was a considerable rise in temperature, carbon dioxide was evolved and the ammonium salt of acetylalanine crystallised out The explanation of this reaction is based upon Erlenmeyer and Kunlin s synthesis of phenylalanine from phenyl-pyruvic acid and it proceeds as follows —... 

The actual formation of pyruvic acid from various mercapturic acids upon which these formulae for cysteine and cystine were founded, was only shown later by Baumann s pupils, Konigs, Brenzinger and Schmitz, and in conjunction with Suter s observation that a-thiolactic acid was formed by the hydrolysis of horn, this formula for cystine was accepted. The results obtained, however, scarcely justified this formula as pointed out by Friedmann in 1902, who showed conclusively that the cystine, obtained from proteins, had not this constitution. 

More drastic hydrolysis conditions of unsaturated oxazolones 448 leads to further hydrolysis of the intermediate 2-acylamino-2-alkenoic acid 449 and produces the corresponding a-keto acids 450. For example, phenylpyruvic acid " and other aryl(heteroaryl)pyruvic acids of biological interest have been obtained in this manner (Scheme 7.148). 

Recently Benkovic and Schrayl28b and Clark and Kirby,26c have investigated the hydrolysis of dibenzylphosphoenolpyruvic acid and mono-benzylphospho-enolpyruvic acid which proceed via stepwise loss of benzyl alcohol (90%) and the concomitant formation of minor amounts (10%) of dibenzylphosphate and monobenzylphosphate, respectively. The pH-rate profiles for release of benzyl alcohol reveal that the hydrolytically reactive species must involve a protonated carboxyl group or its kinetic equivalent. In the presence of hydroxylamine the course of the reaction for the dibenzyl ester is diverted to the formation of dibenzyl phosphate (98%) and pyruvic acid oxime hydroxamate but remains unchanged for the monobenzyl ester except for production of pyruvic acid oxime hydroxamate. The latter presumably arises from phosphoenolpyruvate hydroxamate. These facts were rationalized according to scheme (44) for the dibenzyl ester, viz. 

The enol of 2-oxopropanoic acid (pyruvic acid) is of special biological interest because the phosphate ester of this compound is, like ATP (Section 15-5F), a reservoir of chemical energy that can be utilized by coupling its hydrolysis (AG° = —13 kcal) to thermodynamically less favorable reactions ... 

A general route to aryl-substituted pyruvic acids (e.g. phenylpyruvic acid, Expt 5.175) is the acid hydrolysis of 2-acetamido-3-arylacrylic acids (19), which are themselves formed by hydrolysis of the corresponding azlactones (18) (cf. Expt 8.21) with water. 

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