Glyoxylic acid,

Oxaloacetic acid, the starter compound of both the TCA and the glyoxylate cycles is regenerated from malic acid under the action of malate dehydrogenase. In green plants, oxaloacetic acid can normally be supplied in any amount needed for operation of the cycles from phosphoenol pyruvate. Oxaloacetic acid is the initial product of CO2 fixation in C4-photosynthetic and Crassulacean acid pathways. In these pathways, oxaloacetic acid is formed by yff-carboxylation of phosphoenol pyruvate catalyzed by phosphoenol pyruvate carboxylase. 

Glyoxylic acid as an intermediate in the glyoxylate cycle is formed by the cleavage of isocitric acid catalyzed by isocitrate lyase. This acid is also an oxidation product of glycolic acid during photorespiration. This reaction is carried out by gly-colate oxidase, which is localized in peroxisomes. 

Condensation of phenols with glyoxylic acid in basic media to furnish substituted mandelic acids, which yield the corresponding aldehyde on homogeneous catalytic oxidative de-carbonylation. Information regarding the process is mostly confined to patent literature (Eq i 43) 126,127,128 conversion of phenol to p-hydroxybenz- 

A negative aspect of this reaction is the formation of unwanted di-mandelic acid side-products due to the higher reactivity of the 2- and 4-hydroxymandelic acid compared to phenol. Formation of these side-products is minimized by the addition of excess phenol, 

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Glyoxylic acid solution (protein detection) cover 10 g of magnesium powder with water and slowly add 250 mL of a saturated oxalic solution, keeping the mixture cool filter off the magnesium oxalate, acidify the filtrate with acetic acid and make up to a liter with water. 

Glyoxal [108-22-2] Glyoxal Resins Glyoxal resins Glyoxylic acid... 

Glycohc acid also undergoes reduction or hydrogenation with certain metals to form acetic acid, and oxidation by hydrogen peroxide ia the presence of ferrous salts to form glyoxylic acid [298-12A], HCOCOOH, and ia the presence of ferric salts ia neutral solution to form oxaHc acid, HOOCCOOH formic acid, HCOOH and Hberate CO2 and H2O. These reduction and oxidation reactions are not commercially significant. 

Isothiazole-4,5-dicarboxylic acid, 3-phenyl-dimethyl ester synthesis, S, 150 Isothiazole-5-glyoxylic acid ethyl ester reduction, 6, 156 Isothiazole-4-mercurioacetate reactions, 6, 164 Isothiazole-5-mercurioacetate reactions, 6, 164 Isothiazoles, 6, I3I-I75 acidity, 6, 141 alkylation, 6, 148 aromaticity, S, 32 6, 144-145 basicity, 6, I4I biological activity, 6, 175 boiling points, 6, I43-I44, 144 bond fixation, 6, 145 bond orders, 6, I32-I34 calculated, 6, 133 bromination, S, 58 6, 147 charge densities, 6, 132-134 cycloaddition reactions, 6, 152 desulfurization, S, 75 6, 152 deuteration, S, 70... 

Di-(/)-chlorophenyl)-acetic acid has been made by the action of alcoholic potassium hydroxide on l,l-di-(/>-chlorophenyl)-2,2-dichloroethane by the action of barium hydroxide on DDT in ethylene glycol and by the condensation of chlorobenzene with glyoxylic acid. ... 

Tribromobenzoic acid has been prepared by the deamination of 2,4,6-tribromo-3-aminobenzoic acid (reagents not specified), by hydrolysis of 2,4,6-tribromobenzonitrile, " and by oxidation of the tribromotoluene, the benzyl chloride, the aldehyde,and the glyoxylic acid.i The present method is a modification of that of Bunnett, Robison, and Pennington.i ... 

In a situation where severe steric hindrance e.g., 16,16-dimethyl-20-keto-pregnanes) prevents enol acetate formation, an alternate scheme has been devised. Condensation of ethyl oxalate at C-21 produces, after hydrolysis, the 21-glyoxylic acid this on treatment with acetic anhydride and a strong acid catalyst such as perchloric acid gives both lactone acetates. 

A mixture of 10 g of the glyoxylic acid, 100 ml of acetic anhydride, and 0.5 g of 2,4-dinitrobenzenesulfonic acid is stirred at 25° for 2 hr. Sodium acetate (0.5 g) is added and the mixture concentrated in vacuum at 50°. The residue is taken up in 100 ml of benzene and washed with two portions of 2.5 N sodium hydroxide to remove the remaining acetic anhydride. The benzene solution is washed with water, dried and concentrated in vacuum to dryness. Crystallization from 40 ml of absolute ethanol gives 9.8 g (85%) of 3a,20,23-trihydroxy-16a-methyl-11 -oxo-21 -norchola-17(20),22-dienoic acid-24(20)-lactone 3,23-diacetate mp 165-175°. 

Hydroxy-6-methyl-10 (5 6) abeo-cholestan-5-one acetate, 391 3 a-Hydroxy-16a-methyl-11,20-dioxo-5/3-pregnane-21-glyoxylic acid, 191 17 -Hydroxy-l-niethyl-A-homo-5a-androst-l-en-3-one acetate, 362 17 /3-Hy droxy-5a, 1 Oa-methy lene-A-norestran-3-one, 429 17 3-Hydroxy-17 a-methyl-10 ( 5 4) -fl( < o-estrane-3,5-dione, 314 3a-Hydroxy-16a-methyl-5/3-pregnane-11,20-dione, lyl... 

A weak cation-exchange resin is obtained by reaction of glyoxylic acid and a cross-linked polyvinyl alcohol. The polyvinyl alcohol is cross-linked with glutaraldehyde in the presence of hydrochloric acid. The cation-exchange resin has an exchange capacity of 3 meq/g or greater and a swelling volume of 10 ml/g or smaller (37-38). 

TosMIC reagents. For example, glyoxylic acid ethyl ester undergoes cycloaddition with (2-naphthyl) tosylmethyl isonitrile (17) to produce oxazole 18 in good yield. ... 

With semicarbazones of lower a-keto acids the reaction proceeds with some difficulty or not at all. Thus, the semicarbazones of pyruvic acid cannot be cyclized and that of glyoxylic acid is predominantly hydrolyzed so that the yield of the cyclization product is only 20-25%. ° This reaction was used in work with a different object, for preparing 6-azauracil, for the first time. 

The starting semicarbazones were most often prepared directly from the a-keto acids. Godfrin proceeded from a-alkyl acetoacetates, which were converted by oxidation with nitrosylsulfuric acid to a-keto-acid oximes and the latter transformed to semicarbazones or thioseraicarbazones by applying semicarbazide or thiosemicarbazide. For glyoxylic acid semicarbazone a very convenient procedure was employed, making use of the hydrolysis of nonisolated chloral semicarbazone. ... 

In a further synthesis, Gut ° used the cyclization of the thiosemi-carbazone of glyoxylic acid (56) the 2-thioxo-5-oxo-2,3,4,6-tetra-hydro-l,2,4-triazine (57) formed was converted to 6-azauracil by applying aqueous solution of chloroacetic acid. (This reaction will be discussed later, e.g.. Section II,B,4,b.) The same procedure was used... 

A uniformly favorable effect is displayed by an alkyl group, in position 2. Thus the 2-methylthiosemicarbazone of pyruvic acid is cyclized at normal temperature and without excess hydroxide. The 2-methylthiosemicarbazone of glyoxylic acid (98) was cyclized by boiling for 5 min to 2-methyl-3-thioxo-5-oxo-2,3,4,5-tetrahydro-... 

Substitution in position 4 displays a more complex influence. Cyclization of the 4-methyl- and 4-ethyl-thiosemicarbazones of phenylpyruvic acid and of the 4-methylthiosemicarbazone of phenyl-glyoxylic acid (103) was readily achieved (104), whereas it was not possible to cyclize the analogous 4-methyl derivatives of pyruvic and glyoxylic acids. It thus appears that cyclization is hindered by substitution in position 4 and that this unfavorable effect can be partly relieved by the known favorable effect of an aryl or aralkyl group in the a-position. 

In a study of the nitrosation of camphor-3-glyoxylic acid (89), Chorley and Lapworth isolated a compound whose structure (90) has recently been clarified by Hatfield and Huntsman. Decarboxylation and ring expansion occur and the reaction is rationalized in the sequence 89 90. The buttressing effect of a methyl group on... 

Reductive alkylation has been used to prepare a-amino acids suitable for lactam formation and further elaboration. In a single step a carbobenzyloxy group was removed, and alkylation with glyoxylic acid hydrate was achieved (18). 

Glyoxylic acid ethyl ester ethyi alcoholate Manufacturing Process... 

On the basis of experiments with myoinositol (50), it has been suggested that triose reductone should be oxidized by periodate to yield two molar equivalents of formic acid and one molar equivalent of carbon dioxide. However, it has been reported by two groups (1,29) that crystalline triose reductone is oxidized by two moles of periodic acid to give formic acid and glyoxylic acid, free iodine being liberated during the... 

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