Methyl-3-methylbutyrate

Monobasic solutes that have no carbinyl hydrogens may also show nonequivalence. 3-Methyl-2-butanone, 4-methyl-2-pentanone, 2-methylpropanal, methyl 2-methylbutyrate, 2,2,6,6-tetramethyl-piperidine, methyldiisopropylcarbinol, and methylethyl-n-butyl-carbinol in TFAE-saturated benzene all show nonequivalence of sufficient magnitude (0.01-0,03 ppm) to allow nonequivalence sense determination at 220 MHz. An especially striking example is that provided by pyrazolines 26. With only a severalfold excess of (S)-TFAE, 3(5),5(S)-enriched samples of these compounds show nonequivalence in their methyl resonances (downfield sense for the singlets and upfield sense for the triplets) sufficient for enantiomeric purity determination at 90 MHz (52). 

Methyl 2-Methylbutyrate FEMA No. 2719 Methyl 2-Methylbutanoate 116.16/C6H1202/ ch3oocchch2ch3 ch3 almost colorless liq/ sweet, fruity, apple s—ale, most fixed oils ins—water/ 115° ... 

Blank and Grosch [91] have identified carvone as main odour carriers in seed oil, whereas in the leaf oil dill furan, myristicin, methyl 2-methylbutyrate, limonene and -phellandrene are responsible for the typical odour. See also [92],... 

Butanoic acid, 2-methyl- 2-methylbutyric acid 172a 174a, 174b, 603, 3370... 

Methyl o-methoxybenzoate Methyl 2-methylbutyrate Methyl 3-methylthiopropionate Methyl 4-methylvalerate Methyl myristate... 

This essential oil, distilled from Chamaemelum nobile (L.) All., possesses a series of angelates in various concentrations. Bail (2009) published the following values for angelates and sped c esters isobutyl angelate 32.1%, 2-methylbutyl angelate 16.2%, isobutyl isobutyrate 5.3%, methyl 2-methylbutyrate 1.9%, prenyl acetate 1.4%, 2-methylbutyl 2-methylbutyrate 1.2%, and 2-methylbutyl acetate 1.2%. As most of these compounds are available as synthetic chemicals, adulteration can be done easily. Detection is done by the combination of GC-C-IRMS. 

As mentioned with relation to the acids when the alpha carbon carries a substituent the rearrangement ion shifts in mass by the mass of the substituent. The isomeric pentonates, methyl isovalerate and methyl 2-methylbutyrate can readily be distinguished (Tanaka and Yu, 1973) because of the formation of mh 88 in the latter. 

In addition, the different points of alkyl branching in the two compounds give rise to differences in the hydrocarbon fragments, namely that and 4 are the favoured fragments in the respective spectra of methyl isovalerate and methyl 2-methylbutyrate. 

The 5-methyl-5-ethyloxazolidine-2,4-dione may be prepared by reacting methyl ethyl ketone with sodium cyanide and with ammonium thiocyanate followed by desulfurization. This intermediate may also be prepared by condensing a-hydroxy-a-methylbutyramide with ethyl chlorocarbonate or by condensing ethyl a-hydroxy-a-methylbutyrate with urea. Another method described (Traube and Aschar, Ber., 46, 2077-1913) consists in the condensation of ethyl a-hydroxy-a-methylbutyrate with guanidine followed by hydrolysis. 

Chemical Name 2-Methylbutyric acid 9-ester with 9,10-dihydro-9,10-dihydroxy-8,8-di-methyl-2H,8H-benzo[1,2-b 3,4-b l dipyran-2-one acetate... 

C2jH3 07 67212-74-2) see Alclometasone dipropionate 2 -hydroxy-4 -(3-methyl-2-butenyloxy)acetophenone (C,3H] 03 24672-83-1) see Sofalcone 2-hydroxy-2-methylbutyric acid ethyl ester (C7H14O3 77-70-3) see Paramethadione 2-hydroxy-2-methylbutyronitrile (Ci H NO 4111-08-4) see Paramethadione 5(R)-(hydroxymethyl)-2-cyclopenten-l(R)-ol (C(jH,(,02 143395-28-2) see Abacavir 2-[l-(hydroxymethyl)cyclopropyl]acctonitrile (QH9NO 152922-71-9) see Montelukast sodium ( )-cis-2-hydroxymethyl-Af,Af-diethyl-l-phenylcyclo-propanecarboxamide... 

Mercaptobutane 2-Mercaptoethanethiol 2-Methallyl Chloride 2-Methylallyl Chloride 2-Methyl-Allylchlorid 2-Methylbutanoic Acid 2-Methylbutyric Acid... 

Chemical name (F S)-a-cyano-3-phenoxybenzyl(F S)-2-(4-chlorophenyl)-3-methylbutyrate cyano(3-phenoxyphenyl) methyl 4-chloro-a-(1-methylethyl) benzeneacetate a-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)-3-methylbutyrate 4-chloro-a-(1 -methylethyl) benzeneacetic acid cyano(3-phenoxyphenyl) methyl ester a-cyano-3-phenoxybenzyl a-(4-chlorophenyl) isovalerate... 

Phoracantha species contained 6-methylsalicylic aldehyde 191, the dis-ubstituted cyclopentene phoracanthal 192, the corresponding alcohol, phora-canthol, and the (E)- and (Z)-stereoisomers of the saturated system. In addition, methyl and ethyl esters of 2-methylbutyric acid and isovaleric acid as well as the macrocyclic lactones decan-9-olide (=phoracantholide I), (Z)-dec-4-en-9-olide (=phoracantholide J) 193, and 11 -hydroxytetradec-5-en-13-olide 194 [8,355, 356]. As shown by independent syntheses of both enantiomers, the natural phoracantholides show ( -configuration [357]. 

Simvastatin is a semi-synthetic statin that is produced from the natural statin lovasta-tin7 Both are potent antihypercholesterolemic agents with simvastatin differing from lovastatin by just one additional methyl substituent residing on the 2-(5)-methylbutyrate side chain (Figure 1.6). 

The methyl ester of operculinic acid E was obtained by basic hydrolysis and methylation of the crude resin glycoside mixture of 7. murucoides. Mumcoidins XII (53) and XIII (54) afford operculinic acid E as their oligosaccharide core. The lactonization site was placed at C-3 of the first rhamnose unit. These resin glycosides contain an esterifying residue that is composed of n-dodecanoic or (25)-methylbu-tyric acids at the C-2 or C-3 positions on the second rhamnose unit of the oligosaccharide core and (25)-methylbutyric acid at C-4 on the third rhamnose (30). 

Eight naturally occurring, structurally related avermectins are produced by Streptomyces avermitilis [7], The avermectin polyketide structure is derived from seven acetate and five propionate residues, together with a single 2-methylbutyric acid or isobutyric acid residue which forms the sec-butyl or isopropyl group attached to the C25 of the spiroketal moiety [8,9] (Fig. 1). The avermectin agly-cone is further modified by glycosylation at C13, with the attachment of two O-methylated oleandrose residues and O-methylation at C5. Thus, S. avermitilis... 

As mentioned, fermentation is used to provide the core structure of simvastatin, and hydrolysis is used to remove the 2-methylbutyrate sidechain the dimethylbutyric acid sidechain is introduced by coupling (Scheme 31.6).70-73 Chemical methylation to form the quaternary dimethylated center in the sidechain has been achieved on synthetic intermediates.7475 The chemical approach has to differentiate two hydroxy groups, and this requires protection-deprotection steps.76-86... 

Type 3 fermentation, characterised by a series of reactions between mitochondrial end-products that yield branched-chain fatty acids (e.g. 2-methylvalerate, 2-methylbutyrate), occurs in Ascaris, a number of other intestinal nematodes and in some trematodes (490). However, cestodes, with the exception of Bothriocephalus scorpii, which excretes methyl-butyrate (107), have not been shown to produce branched-chain fatty acids as end-products of respiratory metabolism. Some or all of the enzymes of the TCA cycle may be present in cestodes in addition to the type 1 and type 2 fermentation pathways. The extent to which the cycle may contribute to carbohydrate metabolism in cestodes is considered below. 

Methylbutyric Acid, 82 Methyl Ionones, 82 Methyl Isobutyrate, 82 Methyl-3-methylthiopropionate, 82... 

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