Pentanoate esters

Ethylenedithio)pentanoate Ester (Levulinoyldithioacetal Ester ROLevS y— ... 

Keywords 4,5-dihydroxy-2-pentenoic ester, amine, Michael 1,2-addition, asymmetric induction, microwave irradiation, 3-amino-4,5-dihydroxy-pentanoic ester... 

Ethylenedithio)pentanoate esters, to protect alcohols, 97-98 Ethyl enol ethers, to monoprotect dicarbonyls, 220... 

GVL 73, itself a potential biofuel, is also a starting material for pentanoate esters ( valeric biofuels ) that have been shown to have outstanding fuel properties [213]. GVL-derived pentanoic acid 80 can be catalytically upgraded by decarboxylative ketonization to 5-nonanone 81, which can then be variously processed to nonane 82 and other hydrocarbons [214, 215], GVL has also been converted to butenes over a silica-alumina catalyst, which are then oligomerized on H-ZSM-5 or Amberlyst-70 to give a mixture of Cg-Cie alkenes that can be hydrogenated to drop-in fuels (Scheme 27) [216]. 

Ho=Hoechst. Probably obsolete. Sum for Type I and butenal vitamin-A precursor. 3 kt/a sum for B and valerolactone. L =bulky monophosphite. Plus propanoic acid, methyl methacrylate. Plus pentanoate esters. 

The sequence begins with a Claisen condensation of ethyl pentanoate to give a p keto ester The ester is hydrolyzed and the resulting p keto acid decarboxylates to yield the desired ketone... 

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)... 

ID) Obtaining Ethyl [3-l6-Methoxy-2-Naphthyl)J2,2-Dimethyl Pentanoate by Hydrogenation of the Previous Ethylene Ester 3.5 g of the previous ethylene ester, purified by chromatography, are hydrogenated in the presence of 3.6 g of platinum in 30 cc of ether. The quantity of hydrogen fixed corresponds to the theoretical quantity calculated. After filtering, the ether is evaporated, 3.45 g of ester are thus obtained in the form of an oil which quickly solidifies. Purification is effected by chromatography. 

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. 

Bates, Hewlett, and Lloyd (I) found that both piperonyl butoxide and SKF 525A, the ester of 2-diethylaminoethyl 2,2-diphenyl-w-pentanoate, synergized the action of pyrethrins on insects of species of the lesser mealworm beetles and houseflies but both antagonized the action of malathion. SKF 525A is known to increase the effects on mammals of drugs of various types and has been shown to synergize pyrethrins. 

Bates, Hewlett, and Lloyd (2) therefore studied the synergistic effects of some compounds related to 2-diethylaminoethyl 2,2-diphenyl-w-pentanoate on the insecticidal activity of pyrethrins. They found active compounds when a 2-diethylamino moiety was joined to the diphenylmethyl moiety through an ester, ketone, or ether linkage. However, none of the compounds investigated approached piperonyl butoxide in synergistic activity with pyrethrins. 

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... 

Substituted cyclopropanols were also obtained, albeit in moderate yields, upon reaction of esters such as methyl pentanoate with l,4-bis(bromomagnesium)butane (38) in the presence of titanium tetraisopropoxide. This corroborates the formation of a titanacy-clopropane—ethylene complex 40 from an initially formed titanacyclopentane derivative 39 (Scheme 11.12) [103], Apparently, an ester molecule readily displaces the ethylene ligand from 40, and a subsequent insertion of the carbonyl group into the Ti—C bond, a formal [2S + 2J cycloaddition, leads to the oxatitanacyclopentane 42, the precursor to 1-butylcyclopropanol (43). 

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... 

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