2-Ethyl-3-hexenoic acid

CN ( )-6-(l,3-dihydro-4-hydroxy-6-methoxy-7-methyl-3-oxo-5-isobenzofuranyl)-4-methyl-4-hexenoic acid 2-(4-morpholinyl)ethyl ester... 

Butenoate Ethyl 3-Methyl-4,4,4-trifluoro- ElObj. 54 (Educt) 4-Hexenoic Acid Trifluoromethyl-E10b2. 2221". [F3C-CH2-C. 0-0-CH(CH3)-CH = CH2 R3Si-X/ Base]... 

E10b2. 373 (-C1F - En) 4-Hexenoic Acide 2.5-Dimcthyl-2-fluoro- E10b2. 22.3 (H3C-CHF-C0-0-CR2-CH = CH2/R3Si—X/Base) 4-Pentenoate Ethyl 2-Fluoro-3-methyl- E10b2, 204f. (F - OR) 4-Pcntenoie Acide 2-Fluoro-3-... 

A suspension of ethyl 4-trichloroacetoamido-5-hexanoate (0.3 g, 1 mmol) in 6 N HCI (10 mL) was heated under reflux 6 hours. Then the mixture was concentrated in vacuo, diluted with water (10 mL), washed twice with AcOEt, and dried in uacuo to give the title product (0.18 g, 100%). NMR, TLC (NH4OH EtOH, 3 7) are identical with those of an authentic sample of 4-amino-5-hexenoic acid. 

The ethyl ester of diphenesenic acid residue is dissolved in ethanol. H20 and KOH are then added and the mixture is heated under reflux for 2 h. The alcohol is evaporated under vacuum. The residue is dissolved in H20. Aqueous solution is washed with petroleum ether. The solution is then decolorized with active carbon and acidified slowly with HCI 10% till pH 2.1. After stirring at room temperature for 4 h the solid product is filtered, washed with H20 till washing liquid is neutral. The solution is then dried under vacuum at 50°C. So the 2-[4-biphenylyl]-4-hexenoic acid (diphenesenic acid), melting point 118-119°C (crystallized from cyclohexane), boiling point 182-183°C is obtained. 

The epoxide can be prepared from an alkene and the amide from a carboxylic acid. The new target. 2-ethyl-2-hexenoic acid, has a CC double bond in conjugation with the carbonyl group of the carboxylic acid. Whenever a compound with an ,/3-unsaturated carbonyl group is encountered, it is worthwhile to consider the possibility of using an aldol condensation (see Section 20.5) or a related reaction to prepare it. To examine this possibility, the aldehyde that will provide the carboxylic acid upon oxidation is disconnected at the double bond. Because both fragments produced by this disconnection are the same, it is apparent that an aldol condensation of butanal can be employed to prepare this compound. The synthesis was accomplished as shown in Figure 23.5. 

The a-bromine atom is stable during lactone formation from a,y-dibromo-butyryl bromide the yield of a-bromo lactone is 94%. Under similar conditions the /3-bromine atom of /3,y-dibromohexanoic acid is eliminated as hydrogen bromide to give the lactone of 4-hydroxy-2-hexenoic acid. Cyclization of alkali salts of 15-bromopentadecanoic acid has been studied using various solvents and concentrations. Best yields of the O)-lactone are obtained from the potassium salt in methyl ethyl ketone. ... 

C8H1402 2-ethyl-2-hexenoic acid 5309-52-4 510.00 44.846 2 14714 C8H1404 2,5-dihydroperoxy-2,5-dimethylhex-3-yne 3491-36-9 495.09 43.413 2... 

Formation of 2-Ethyl-2(5H) Furanone. The presence of artifacts with increased retention times suggests the formation of components of increased polarity and/or the formation of higher molecular weight constituents from condensation or addition reactions. The acids, aldehydes and alcohols present can undergo oxidation to form y- and 6-lactones (14, 15). The formation of the lactone, 5-ethyl-2(5H)-furanone, probably occurs by the steps outlined in Figure 4. A plausible sequence would be reaction of 2-hexenoic acid to form a peroxy radical at the y-position followed by production of the hydroperoxide. Cleavage of the 0-0 bond with the subsequent addition of H could lead to 4-hydroxy-2-hexenoic acid. Intramolecular esterification would then produce the identified lactone. 

Figure 4. Possible mechanism for the formation of 5-ethyl-2(5H)-furanone from 2-hexenoic acid.

G.13) 2(5/f)-Furanone, 5-ethyl-3-hydroxy-4-methyl-, 2-hydroxy-3-methylhex-2-eno-4-lactone, 5-ethyl-2,5-dihydro-3-hydroxy-4-methylfuran-2-one, 4-ethyl-2-hydroxy-3-methyl-2-buten-4-olide, 2,4-dihydroxy-3-methyl-2-hexenoic acid, 7-lactone, a-hydroxy-p-methyl-Aa,p-7-hexenolactone, abhexone 698-10-2] FEMA 3153 ( )- 1144810-13-9] (/ )- 144831-60-7J (5)- 14483l-61-8]... 

Dehydroacetic Acid. 3-A cctyl-b-melhyl 2H-py-ran-2,4(3H)-dione 2-acetyl-5-hydroxy-3-oxo-4-hexenoic acid i-lactone methylacetopyronone DHA. CjHjO mol wt 168.]4. C 57.14%, H 4.80%, O 38.06%. Polymerization product of ketene Steele er al. J. Org. Chem. 14, 460 0949)- From ethyl acetoacetate Arndt, Org. Syn. coll, vol. Ill, 231 (1955). Series of articles on toxicity studies, pharmacology, mechanism of action, absorption, distribution, renal action J. Pharmacol. Exp Ther. 99, 57-111 (1950). 

Ethyl-6-methoxypyrazine 204 3-Hexenoic acid 252 Linalool oxide... 

FK-409(4-ethyl-2-hydroxyimino-5-nitro-3-hexenoic acid amide). 

Pierce, Jr., J. D., Blank, D. H., Aronov, E. V., Guo, Z., Preti, G., and Wysocki, C. J., 1996, Cross-adaptation of sweaty-smelling 3-methyl-2-hexenoic acid by its ethyl esters is determined by structural similarity, J. Soc. Cosmet. Chem. 47 363-75. 

The effect of the catalyst and the hgands has not been discussed yet however, it plays an important role. For example, by replacing the classical phosphine ligands by a hydrosoluble sulfonated triphenylphosphine (TPPTS), Safi and Sinou carried out a reaction with butadiene monoxide and ethyl acetoacetate in a two-phase aqueous-organic medium.f The recycled water layer containing the catalyst could be reused with very high efficiency for a second reaction. As a matter of fact, the corresponding ethyl ester of the 2-acetyl-6-hydroxy-4-hexenoic acid was isolated in 80% and 87% yield (Z/E = 15 85) after the first and the second reaction, respectively. 

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