Valeric 2-hydroxy-2-methyl-

CiiHnNO 84080-68-2) see Cefixime 17,21-(l-butyl-l-methoxymcthylenedioxy)-3,20-dioxo-9-fluoro-lip-hydroxy-l(Sa-methyl-l,4-pregnadiene (C2gH3gF06 1062-64-2) see Dexamethasone valerate S-(crt-butyl 3-methyl 2,6-dimethyl-4-(3-nitrophenyl)-l,4-dihydropyridine-3,5-[Pg.2319]

P-METHYL-8-VALEROLACTONE (Valeric acid, 5-hydroxy-3-methyl-, 8-lactone)... 

Recently, two new beauvericins were discovered [56], These beauvericins are composed of L-phenylalanine, D-2-hydroxy-3-methyl-valerate, and D-2-hydroxyisovalerate, yielding mixed-type structures. 

In 1941 Gakhokidze40 realized a different type of Grignard synthesis on a carbohydrate acid derivative. Methyl L-ery(liro-3,4,5-trimethoxy-2-oxovalerate (XXXII), was treated with one mole of methylmagnesium iodide to produce methyl 2-methyl-2-hydroxy-L-er /(firo-3,4,5-trimethoxy-valerate (XXXIII). The configuration of the second carbon atom in... 

Benzyloxy-3-hydroxy-3-methylpentanoic-2-13C acid Valeric-2-13C acid, 5-benzyloxy-3-hydroxy-3-methyl- (8) Pentanoic-2-,3C acid, 3-hydroxy-3-methyl-5-(phenylmethoxy)- (9) (57830-65-6) Acetic-2-13C acid (8,9) (1563-80-0)... 

Wang used reactive-extrusion polymerization with 2,5-di-methyl-2,5-di-t-bu-tylperoxy hexane to prepared a graft copolymer, (11), by free radically grafting polyethylene-glycol malonic acid onto the biodegradable substrate of poly((3-hydroxybutyrate-co- p-hydroxy valerate). 

Esters.— The simplest class of compounds present in essential oils are the esters or ethereal salts (p. 140). In our early discussion of these compounds in the aliphatic series it was stated that the odor and flavor of common fruits is probably due to ester compounds and that certain empirical mixtures of esters are used as artificial fruit essences. Artificial apple essence, for example, may be prepared by mixing certain proportions of ethyl nitrite, ethyl acetate and amyl valerate with chloroform, aldehyde and alcohol. An example of an essential oil which consists of a single ester is oil of wintergreen. vAdxh is the methyl ester of salicylic acid, ortho-hydroxy benzoic acid (p. 714). 

Valeric acid, a-ACETYL- -CHLORO-7-HYDROXY-, y-LACTONE, 31, 1 5-HYDROXY-3-METHYL, 5-LACTONE,... 

Valeric acid, a-ACETYL-5-CHLORO-y-HYDROXY-, 7-LACTONE, 31, 1 S-HYDROXY-3-METHYL-5-LACTONE, 35, 86... 

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],...

Hydroxy-4-octanone Isoamyl propionate Isobutyl butyrate Isobutyl isobutyrate Isooctanoic acid Isopropyl isovalerate Isopropyl 2-methyl butyrate Isopropyl valerate Methyl amyl acetate Methyl heptanoate 2-Methylheptanoic acid Propyl isovalerate Propyl valerate... 

Hydroxybutyrate 3-Hydroxyhexanoate 3-Hydroxy-4-methyl valerate 3-Hydroxyvalerate Infrared... 

Important components of hard cheeses (Gouda type) include some carboxylic acid esters (ethyl butanoate, ethyl hexanoate), as well as carboxylic acids (acetic, butyric, isobutyric, valeric, isovaleric, 2-methylbutyric and caproic acids). Cheeses manufactured using bacteria of the genus Propionibacterium (such as Emmental and Gruyere) contain propionic acid and other lower fatty acids, methyl thioacetate, some oxocarboxylic acids, various alcohols, esters (such as ethyl butanoate), lactones (such as 8-decalactone), amines and other basic compounds (also skatole in addition to aliphatic amines), alkylpyrazines (e.g. 2-sec-butyl-3-methoxypyrazine), 4-hydroxy-2,5-dimethyl-2H-furan-3-one (furaneol), 2-ethyl-4-hydroxy-5-methyl-2H-furan-3-one (homofuraneol) and a range of other compounds. 

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). 

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