A-Methyl valeric acid

Methyl butyric acid Isovaleric acid -h trimethyl acetic acid a-Methyl valeric acid Cg-Acids... 

Pimelic acid, a-methyl valeric acid Suberic acid, methyl hexanoic acid Decane-l,10-dicarboxylic acid Dodecane-1,12-dicarboxylic add Tetradecane-l,14-dicarboxylic acid... 

C) dl-Isoleucine.—One hundred and fifty grams (0.77 mole) of a-bromo-/3-methyl valeric acid is added to 645 cc. of technical ammonium hydroxide (sp. gr. 0.90) in a 1.5-I. round-bottomed flask. A stopper is wired in and the flask allowed to stand at room temperature for a week (Note 9). The stopper is removed and the mixture heated on a steam cone overnight to remove ammonia. The aqueous solution is concentrated under reduced pressure until bumping becomes violent (about 300 cc.). The mixture is then cooled to 150 and the crystals collected on a filter. The crystals are washed with 40 cc. of alcohol and dried. The filtrate is again concentrated to about 150 cc. and a second crop of crystals obtained. This second crop is washed with 25 cc. of water and then with 25 cc. of 95 per cent alcohol. The yield of crude product is 65 g. 

Diastereoisomers. Whereas compounds with one chiral center exist as an enantiomorphic pair, molecules with two or more chiral centers also exist as diastereoisomers (diastereomers). These are pairs of isomers with an opposite configuration at one or more of the chiral centers, but which are not complete mirror images of each other. An example is L-threonine which has the 2S, 3R configuration. The diastereoisomer with the 2S, 3S configuration is known as i-a//o-threonine. L-isoleucine, whose side chain is -CH(CH3) CH2CH3, has the 2S, 3R configuration. It can be called 2(S)-amino-3(R)-methyl-valeric acid but the simpler name L-isoleucine implies the correct configuration at both chiral centers. 

This is a general method for preparing a-bromo acids. By using exactly analogous directions -bromo- -caproic acid may be obtained in 65-70 per cent yields from w-butylmalonic ester a-bromo-isocaproic acid in 65-70 per cent yields from isobutylmalonic ester and a-bromo-/3-methyl valeric acid in 75-80 per cent yields from sec.-butylmalonic ester. 

Replacement of the benzene ring with an -butyl segment has been disclosed Scheme 3.124) [73, 248], Thus, methylation of 5-(A,-tosylamino)valeric acid [250], followed by coupling with diethyl L-glutamate, detosylation, alkylation with (26) HBr and hydrolysis afforded (594). 

SYNS a-AMINOISOCAPROIC ACID 2-AMINO-4-METHYLPENTANOIC ACID O-AMINO-y-METHYL-VALERIC ACID 2-AMINO-4-METHYLVALERIC ACID 1.2-AMINO-4-METHYLVALERIC ACID LEUCIN (GERMAN) LEUCINE NORVAUNE, 4-METHYL- VALERIC ACID, 2-AMINO-4-METHYL-... 

Iso-valeric acid is one of the isomeric five carbon acids. It is 3-methyl butanoic acid. Valine is the alphchdimmo derivative of it. a-Amino Valeric Acid, CH3—CH2—CH2—CH(NH2)—COOH... 

Leucine. Leu (1UPAC abbrev ) 2-amino-4-methyl valeric acid a -aminoisocaproic acid 2 -amino -4-methyl -pentanoic acid, C4H13NO, mol wt 131.17. C 54.94%, H 9.99%, N 10,67%, O 24.40%, (CH3)JCHCH2CH(NHi)-COOH. An amino acid classified as essential for maintaining growth in rats. Essential component in human nutrition, not synthesized by the human body. so]n from gluten, casein, keratin Barnett, J. Blot Chem. 108, 543 (1933) U.S. pat. 2,009,868 by electrical transport from blood-corpuscle paste Cox et at, J. Biot Chem. 81,755(1929). Purification and separation from methionine Fox, Science 84, 63... 

Methallenestril. (3-Ethyl-6-tnethoxy-a,a-dimeth-yl-2-naphthalcnepropionic odd- (3-(6-methoxy-2-naphthyl)-tt,a- dimethyl valeric acid 3-(6-methoxy-2-naphthyl)-2,2 -di methyl pen tan oic acid Vallestril. mol wt 286.36. 

AI3-08899 a-aminoisocaproic acid (S)-2-Amino-4-methylpentanoic acid 2-Amino-4-methylpentanoic xid (L) 2-Amino-4-methylpentanoic acid, (S)- a-amino-y-methylvaleric acid (S)-2-Amino- methylvaleric acid 2-amino-4-methyl-valeric acid 2-Amino-... 

Fig. 3.22. GC separation of keto and hydroxy acids from the urine of a patient with maple syrup urine disease. Top chromatogram, the patient before dietary treatment middle chromatogram, the same patient after two days on a diet bottom chromatogram, a mixture of reference compounds. Peaks 1, lactic acid 2, 2-hydroxyisobutyric acid 3, 2-hydroxybutyric acid 4, pyruvic acid 5, 3-hydroxyisobutyric acid 6, 3-hydroxybutyric acid 7, 2-hydroxyisovaleric acid 8, 2-ketobutyric acid 9, malonic acid (internal standard) 10, 2-methyl-3-hydroxybutyric acid 11, 2-hydroxy-n-valeric acid 12. methylmalonic acid 13, 3-hydroxyisovaleric acid 14a and b, 2-ketoisovaleric acid IS, acetoacetic add 16, 2-hydroxyisocaproic acid 17, 2-hydroxy-3-methylvaleric acid 18a, L-2-keto-3-methylvaleric add 18b, D-2-keto-3-methyl-valeric acid 19, 2-ketoisocaproic acid. Reproduced from [386],...

Allen, T.E. and A.J. Manson The analysis of 3-methyl-valeric acid in tobacco by HPLC 48th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 48, Paper No. 9, 1994, p. 28. 

This reaction was first reported by Marckwald in 1904. It is the synthesis of chiral L-valeric acid (a-methyl propanoic acid) from the pyrolysis of brucine salt of racemic o -methyl-o -ethylmalonic acid. Therefore, it is generally known as the Marckwald asymmetric synthesis. Occasionally, it is also referred to as the Marckwald method. In this reaction, the brucine salts of racemic a-methyl-a-ethylmalonic acid essentially exist as a pair of diastereomers that are separated by fractional crystallization the one with lower solubility is isolated. Upon pyrolysis of such crystalline salt at 170°C, the corresponding brucine salt of L-valeric acid forms upon decarboxylation, resulting in a 10% e.e. In addition, Marckwald defined the asymmetric synthesis as reactions that produce optically active molecules from symmetrically constituted compounds with the use of optically active materials and exclusion of any analytical processes, such as resolution. However, this work was challenged as not being a trae asymmetric synthesis because the procedure was similar to that of Pasteur. In fact, the If actional crystallization of the diastereomers is a resolution process. This process is used as base for many other preparations of chiral molecules, such as tartaric acid and under its influence, the kinetic resolution and tme asymmetric synthesis have been developed in modem organic synthesis. The asymmetric synthesis has been redefined by Morrison and Mosher as the reaction by which an achiral unit of the substrate is converted into a chiral unit in such a manner that the two resulting stereoisomers are produced in unequal amounts. ... 

CAS 73-32-5 EINECS/ELINCS 200-798-2 Synonyms Acetic acid, amino-s-butyl- 2-Amino-3-methylpentanoic acid L-2-Amino-3-methylpentanoic acid 2-Amino-3-methylvaleric acid a-Amino-p-methylvaleric acid Isoleucine (INCI) Norvaline, 3-methyl- Valeric acid, 2-amino-3-methyl Classification A natural protein amino acid Definition Commercial prod, is the naturally occurring L(+)-enantiomer Empirical C6H13NO2... 

MethylbutanoI 2-Methylbutanal a-Oxo-j8-methyl valeric acid Isoleucine... 

Tavormina, P. a., and M. H. Gibbs The metabolism of p, y-dihydroxy-j5-methyl valeric acid by liver homogenates. J. Amer. chem. Soc. 78, 6210 (1956). 

Following the ketol condensation to yield a-acetolactate and a-aceto-a-hydroxybutyrate the question arises as to whether the pinacol rearrangement occurs first to form a-keto-jS-hydroxyisovaleric acid and a-keto-i9-hydroxy- 8-methylvaleric acid (Fig. 7, III), or whether there is prior reduction. The evidence favoring pinacol rearrangement followed by reduction of the a-keto- 3-hydroxy acids is that enzymes have been found in Neurospora and E. coli which catalyze the reduction of synthetically prepared a-keto-(8-hydroxyisovaleric acid and a-keto-j8-hydroxy-/3-methyl-valeric acid to the corresponding a,/8-dihydroxy acids (166, 167). 

Truscott, R. J.W., Pullin, C.J., Halpern, B., Hammond, J., Haan, E. andDanks, D.M. (1979), The identification of 3-keto-2-methylvaleric acid and 3-hydroxy-2-methyl-valeric acid in a patient with propionic acidemia. Biomed. Mass Spectrom., 6,294. 

Esters of medium volatility are capable of removing the water formed by distillation. Examples are propyl, butyl, and amyl formates, ethyl, propyl, butyl, and amyl acetates, and the methyl and ethyl esters of propionic, butyric, and valeric acids. In some cases, ternary azeotropic mixtures of alcohol, ester, and water are formed. This group is capable of further subdivision with ethyl acetate, all of the ester is removed as a vapor mixture with alcohol and part of the water, while the balance of the water accumulates in the system. With butyl acetate, on the other hand, all of the water formed is removed overhead with part of the ester and alcohol, and the balance of the ester accumulates as a high boiler in the system. 

Methyl-60 ,90fBacterium Bacillus lentus Valeric acid chloride... 

After further working up there is obtained an oily crystalline residue which is subjected to chromatography on silica gel. The 16a-methyl-6a,9a-difluoro-A -pregnadien-11/3,21-diol-3,20-dione is eluated with ethyl acetatereacted with valeric acid chloride to give the valerate ester. 

For testing sedative hypnotic drugs of the triazolam type the preparation was undertaken of 8-chloro-6-(o-chlorophenyl)-4ff-.y-triazolo[4,3-a][l,4]benzodiazepin-1 -valeric acid methyl ester as an intermediate, with subsequent cyclization and amida-... 

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