Esters 4-pentanoic acid ester

Electrochemical fluorination of a-cyclohexenyl-substituted carboxylic (acetic, propanoic, butanoic, and pentanoic) acid esters (methyl, ethyl, and propyl) results in a series of both perfluoro-9-alkyl-7-oxabicyclo[4 3 OJnonanes and per-fluoro-8-alkoxy-9-alkyl-7-oxabicyclo[4.3.0]nonanes [<8S] (equation 19)... 

Orlistat is a pentanoic acid ester that binds to and inhibits gastric and pancreatic lipases the resulting inhibition of their activity prevents the absorption of about 30% of dietary fat compared with a normal 5% loss. Weight loss is due to calorie loss but drug-related adverse effects also contribute by diminishing food intake. The drug is not absorbed from the alimentary tract. 

A very recent resolution method is the selective hydrolysis of the di-pentanoic acid ester of racemic binaphthol by cholesterol esterase in practice, inexpensive bovine pancreas acetone powder is used, which cleaves only the (Sl-ester42. 

Synonyms Ethyl 3-acetylpropionate Ethyl ketovalerate Ethyl 4-ketovalerate Ethyl y-ketovalerate Ethyl laevulinate Ethyl levulate Ethyl-4-oxopentanoate Ethyl-4-oxovalerate Levulinic acid, ethyl ester 4-Oxopentanoic acid ethyi ester Pentanoic acid, 4-oxo-, ethyl ester Classification Nonaromatic ester Definition Ester of levulinic acid and ethyl alcohol Empirical C7H12O3 Formula CH3COCH2CH2COOC2H5... 

Synonyms Ethyl 2-methylpentanoate 2-Methylvaleric acid ethyl ester Pentanoic acid, 2-methyl-, ethyl ester... 

IE) Obtaining [3-l6-Methoxy-2-Naphthylj]2,2-Dimethyi Pentanoic Acid 2.5 g of the previous ester are saponified by means of 15 cc of soda lye and 25 cc of methyl glycol. 

Benzyl cyanide is first reacted with 2-butylbromide in the presence of sodium amide to give 2-phenyl-3-methylvaleronitrile which is hydrolyzed by sulfuric acid to give 3-methyl-2-phenyl-pentanoic acid. 24 g of 2-phenyl-3-methyl-pentanoic acid are heated for one hour at 175° to 185°C with 30 g of 2-diethylaminoethanol and 0.5 g of sodium methylate. The excess diethyl-aminoethanol is removed in vacuo, the residue is dissolved in 300 cc of 2 N-acetic acid, the acid solution is shaken with ether and made alkaline with concentrated potassium carbonate solution and ice. The ether solution Is washed with water, dried with sodium sulfate and evaporated. The residue is distilled under high vacuum, yielding 20 to 21 g of the basic ester (60% of the theoretical) is obtained, the ester boiling at 98° to 100°C at a pressure of 0.03 mm. The hydrochloride of the ester melts at 112° to 113°C and the methobromide at 100° to 101°C. 

An important example of this reaction is the malonic ester synthesis, in which both Z groups are COOEt. The product can be hydrolyzed and decarboxylated (12-38) to give a carboxylic acid. An illustration is the preparation of 2-ethyl-pentanoic acid from malonic ester ... 

Acetic acid, methyl ester Acetic acid, ethyl ester Pentanoic acid, methylethyl ester Acetic acid, methylethyl ester Acetic acid, 3-propenyl ester Acetic acid, benzyl ester Oxalic acid, dimethyl ester Oxalic acid, diethyl ester Oxalic acid, fe(l-methylethyl) ester... 

Ethyl levulinate Pentanoic acid, 4-oxo-, ethyl ester (539-88-8), 75, 129 ( )-3-Ethyl-1-oxaspiro[3.5]nonan-2-one, 75, 119... 

R. C. Sun and M.Okabe 48 (2S,4S)-2,4,5-TRIHYDROXY-PENTANOIC ACID 4,5-ACETONIDE METHYL ESTER... 

A still different scheme is used for the preparation of the benzimidazole buterizine (74). Alkylation of benzhydrylpiperazine with substituted benzyl chloride 70 gives the intermediate 7U Nucleophilic aromatic displacement on this compound by means of ethyl amine leads to reduction of the nitro group then gives the diamine T. Treatment of that with the orthoformate ester of pentanoic acid serves to form the imidazole ring. There is thus obtained the peripheral vasodilating agent buteri zi ne (74). ... 

Methyl anti-3-hydroxy-2-methylpentanoate Pentanoic acid, 3-hydroxy-2-methyl, methyl ester, (R, R )- )- (11) (100992-75-4)... 

Methyl 4,4-dimethyl-3-oxopentanoate Pentanoic acid, 4,4-dimethyl-3-oxo-, methyl ester (9) (55107-14-7)... 

Pentanoic acid, methylethyl ester BuCOOC—HMe2 387.9... 

Desaturation of alkyl groups. This novel reaction, which converts a saturated alkyl compound into a substituted alkene and is catalyzed by cytochromes P-450, has been described for the antiepileptic drug, valproic acid (VPA) (2-n-propyl-4-pentanoic acid) (Fig. 4.29). The mechanism proposed involves formation of a carbon-centered free radical, which may form either a hydroxy la ted product (alcohol) or dehydrogenate to the unsaturated compound. The cytochrome P-450-mediated metabolism yields 4-ene-VPA (2-n-propyl-4pentenoic acid), which is oxidized by the mitochondrial p-oxidation enzymes to 2,4-diene-VPA (2-n-propyl-2, 4-pentadienoic acid). This metabolite or its Co A ester irreversibly inhibits enzymes of the p-oxidation system, destroys cytochrome P-450, and may be involved in the hepatotoxicity of the drug. Further metabolism may occur to give 3-keto-4-ene-VPA (2-n-propyl-3-oxo-4-pentenoic acid), which inhibits the enzyme 3-ketoacyl-CoA thiolase, the terminal enzyme of the fatty acid oxidation system. 

The ethyl sec,-butylmalonate was prepared from sec-butyl bromide and malonic ester according to the general method described in Org. Syn. 4, n. The yield of ester boiling at i24-i32°/28 mm. was 80-81 per cent of the theoretical amount. The yields of 3-methyl pentanoic acid given in this procedure were obtained with this grade of ester. 

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