4- Ethyl-4-methylbutanoic acid

C7H1402 2-ethyl-2-methylbutanoic acid 19889-37-3 480.15 41.980 1,2 11973 C7H14S 3,3-dimethylthi acycl ohexan e 427.18 36.470 2... 

RN 55937-99-0 MF Ca.HjsClOj MW 346.85 EINECS 259-912-4 CN ( )-2-[4-[(4-chlorophenyl)methyl]phenoxy]-2-methylbutanoic acid ethyl ester... 

This strategy also provides a convenient method for amination of various ester enolates with DPH Ih (Scheme 14). The amination of lithium eniminate of phenyl acetonitrile, the silyl enolate of ethyl phenylacetate and the Reformatsky reagent derived from ethyl a-bromoacetate with DPH were found to be unsuccessful. A failure of DPH for the amination of sodium enolates of S-diketones and the lithium enolate of 3-methylbutanoic acid was also reported . 

Of course, during processing of fruit juices hydrolysis effects may occur, leading to decreased amounts of ethyl 2-methylbutanoate. However, its enantiomeric purity remains unchanged, whilst the corresponding 2-methylbutanoic acid is found as the (S)-enantiomer (99.5% or more) [33-37]. Consequently, the detection of racemic 2-methybutanoic acid (or the corresponding esters) definitely proves the addition of a synthetic (so called nature-identical) flavour compound. 

Figure 10.10 The synthesis of 2R-methylbutanoic acid, illustrating the use of a chiral auxiliary. The chiral auxiliary is 2S-hydroxymethyltetrahydropyrrole, which is readily prepared from the naturally occurring amino acid proline. The chiral auxiliary is reacted with propanoic acid anhydride to form the corresponding amide. Treatment of the amide with lithium diisopropyla-mide (LDA) forms the corresponding enolate (I). The reaction almost exclusively forms the Z-isomer of the enolate, in which the OLi units are well separated and possibly have the configuration shown. The approach of the ethyl iodide is sterically hindered from the top (by the OLi units or Hs) and so alkylation from the lower side of the molecule is preferred. Electrophilic addition to the appropriate enolate is a widely used method for producing the enantiomers of a-alkyl substituted carboxylic acids...

Pravastatin was isolated as products of enzymatic hydroxylation by some kinds of microorganisms of [lS-[l-a(R ),7p,8P(2S, 4S )8a 3]]-2-methylbutanoic acid l,2,3,7,8,8a-hexahydro-7-methyl-8-[2-(tetrahydro-4-hydroxy-6-oxo-2))-pyran-2-yl)ethyl]-l-naphthalenic lactone (campactin) or their carboxylic acid or their salts (products of animal metabolism of microorganisms from the genera Nocardia, Streptomyces et cetera). 

Cacao mass 2-/3-Methylbutanoic acid, 3-methylbutanal, ethyl 2-methylbutanoate, hexanal, 2-methoxy-3-isopropylpyrazine (132), ( )-2-octenal, 2-methyl-3-(methyldisulfanyl)furan (133) 150... 

White wine (Riesling) Ethyl 2-butenoate, ethyl hexanoate, butanoic acid, 3-methylbutanoic acid, methionol (134), 7-undecalactone (135), 4-vinylguaiacol 156... 

SYNS ETHYL ISOVALERATE (FCC) FEMA No. 2463 3-METHYLBUTANOIC ACID, ETHYL ESTER 3-METHYLBUTYRIC ACID, ETHYL ESTER... 

C5H9Br 3-bromo-2-ethyl-1-propene 376.52 33.111 2 5078 C5H9CI02 2-chloro-2-methylbutanoic acid 73758-54-0 473.15 41.31 2... 

If malonate 313 is hydrolyzed and decarboxylated without removing the protecting group, ( S)-4-benzyloxy-3-methylbutanoic acid (317) is produced in 30% overall yield from ethyl L-lactate (2). 

Figure 11 Expansion of the vanilla extract GCxGC-ToF MS chromatogram of the critical propylene glycol region (top) total ion chromatogram and (bottom) combined reconstructed ion chromatograms of m/z 73, 122, and 164 [25]. Peak assignment (5) benzoic acid ethyl ester (6) 2-methylbutanoic acid (7) pentanoic acid (8) 2-phenylethyl acetate.

Apple flavor The sometimes marked differences between aromas of individual varieties of apples are mainly due to quantitative variations in the composition of apple flavor substances. Key components are ethyl (+)-2-methylbutanoate and other esters of 2-methylbutanoic acid, in addition to ethyl and hexyl bu-tanoates, hexyl acetate, (E)-2- and (2)-3-hexenyl acetates (see fruit esters) and j3-damascenone. ( )-2- Hexenal, ( )-2- hexen-l-ol, and hexanal (see alka-nals) play a special role in A. f. These are trace aroma substances in intact apples. When the fruit cells are destroyed, the concentration of the Cg units increase strongly due to enzymatic processes. They are the main aroma components of apple juice. Accordingly, the aromas of fresh apples and apple juice differ markedly. Apricot flavor The typical aroma is due to the combined effects of numerous components with flowery and fruity characters these include linalool, 1-ter-pinen-4-ol, a-terpineol (see p-menthenols), 2-phen-ylethanol, a- and )8- ionones, /5- damascenone, and (Z)-jasmone for the flowery part together with fruit esters and lactones, e. g., 4-octanolide, 4- and 5-deca-nolide, 4-dodecanolide (see alkanolides), hexyl acetate and hexyl butanoate for the fruity part, rounded off by benzaldehyde. 

Strawberry flavor The strawberry aroma is made up of caramel-like [ impact compounds Furaneol, mesifuran (see Furaneol )], fruity [ fruit esters, 4-decanolide (see alkanolides)], green [( )-2- hexen-l-ols, ( )-2- hexenals, 2-hexenyl acetate (see fruit esters)], and flowery notes ( linalool, methyl anthran-ilate). Particularly important fruit esters are ethyl butanoate and hexanoate as well as the corresponding methyl esters. Free acids such as 2-methylbutanoic acid (C5H,o02, Mr 102.13, CAS [116-53-0]) and trace substances, e.g., dimethyl sulfide and vanillin, round off the aroma. 

Potatoes 2-Isopropyl-3-methoxypyrazine together with 2,5-dimethylpyrazine (see pyrazines) dominate in raw potatoes. Key compounds in boiled potatoes are meAional and 2-ethyl-3,6-dimethylpyrazine. Tomatoes The highest flavor values in fresh tomatoes are exhibited by (Z)-3- and ( )-2-hexenals (see alkenals), j3- ionone, hexanal (see alkanals), 8-damascenone, I-penten-3-one (CsHgO, Mr 84.12, CAS [1629-58-9], 3-methylbutanal (see alkanals), and 2-isobutylthiazole. The most important flavor components in tomato pulp are dimethyl sulfide, )8-damascenone, )5-ionone, 3-methylbutanal, I-nitro-2-phenylethane (CgH,N02, Mr 151.16, CAS [24330-46-91), eugenol, methional, and 3-methylbutanoic acid. ... 

Synonyms Ethyl 3-methyl butyrate Ethyl p-methylbutyrate Isovaleric acid ethyl ester 3-Methylbutanoic acid ethyl ester 3-Methylbutyric acid, ethyl ester... 

Methylbutanoic acid ethyl ester. See Ethyl isovalerate... 

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