4-Oxobutanoic ethyl ester

Piperine (25) [56] and trichonine (13) [57] have been prepared by reaction of the corresponding a-sulfonyl organolithium compound with N-(4-oxobutanoyl)piperidine and pyrrolidine, respectively, followed by acetylation of the resulting (3-hydroxy sulfone and final base-promoted double elimination (Scheme 13). Using 4-oxobutanoic ethyl ester, this methodology has been applied to the synthesis of dodecatetraeneamide (19) [23],... 

The synthesis of 4-alkyl-y-butyrolactones 13 and 5-alkyl-<5-valerolactones 14 can be achieved in high enantiomeric excess by alkylation of ethyl 4-oxobutanoate and ethyl 5-oxopentanoate (11, n = 2, 3). The addition of diethylzinc, as well as dimethylzinc, leads to hydroxy esters 12 in high optical purity. When methyl esters instead of ethyl esters are used as substrates, the enantioselectivity of the addition reaction is somewhat lower. Alkaline hydrolysis of the hydroxy esters 12, followed by spontaneous cyclization upon acidification, leads to the corresponding y-butyro- and -valerolactones32. 

The ethyl ester can also be prepared from ethyl acetoacetate (ethyl 3-oxobutanoate) by the method of Rodionov8 as well as via Steinkopf s method.3 Ethyl nitroacetate can be prepared in >70% yields from the dipotassium salt, ethanol, and sulfuric acid, with the addition of anhydrous magnesium sulfate in order to avoid the Nef reaction.9 The propyl and 2-propyl esters can also be obtained by this method. 

Ethyl 4-cyclohexyl-4-oxobutanoate Cyclohexanebutanoic acid, Y-oxo-, ethyl ester (9) (54966-52-8)... 

Glucose-grown cells of G. candidum SC 5469 have also catalyzed the stereoselective reduction of ethyl-, isopropyl-, and tertiary-butyl esters of 4-chloro-3-oxobutanoic acid and methyl and ethyl esters of 4-bromo-3-oxobutanoic acid. A reaction yield of >85% and e.e. of >94% were obtained. NAD+-depen-dent oxido-reductase responsible for the stereoselective reduction of P-keto esters of 4-chloro- and 4-bromo-3-oxobutanoic acid was purified 100-fold. The molecular weight of purified enzyme is 950,000. The purified oxido-reductase was immobilized on Eupergit C and used to catalyze the reduction of (39) to S-( - )-(40). The cofactor NAD+ required for the reduction reaction was regenerated by glucose dehydrogenase. 

ETHYL 4-CYCLOHEXYL-4-OXOBUTANOATE CYCLOHEXANEBUTANOIC ACID, Y-OXO-, ETHYL ESTER (54966-52-8), 65, 17 ETHYL CYCLOPROPYLPROPIOLATE, 66, 173,174 ETHYL (E,Z)-2,4-DECADIENOATE (3025-30-7), 66, 22, 23, 25, 28 Ethyl 3,4-decadienoate (36186-28-4), 66, 22, 28 Ethyl decanoate Decanoic acid, ethyl ester (110-38-3), 67,125 ETHYL DIETHOXYPROPANOATE PROPANOIC ACID, 3.3-DIETHOXY-,... 

The following example shows the self-condensation of ethyl acetate to give ethyl ace-toacetate (ethyl 3-oxobutanoate). Ethoxide is used as the base to avoid transesterification or hydrolysis of the ethyl ester (see Problem 22-34). The initial product is the enolate of ethyl acetoacetate, which is reprotonated in the final step. 

RING EXPANSION AND CLEAVAGE OF SUCCINOIN DERIVATIVES SPIR0[4,5]DECANE-1,4-DIONE AND ETHYL 4-CYCLOHEXYL-4-OXOBUTANOATE (Cyclohexanebutanolc acid.y-oxo-, ethyl ester)... 

A biomimetic synthesis of solerone (5-oxo-4-hexanolide) 1 using both enzymatic and acid-catalyzed reactions was performed. Starting from L-glutamic acid 5-ethyl ester 2 enzymatic oxidative deamination followed by subsequent decarboxylation of the corresponding 2-oxoglutaric acid 5-ethyl ester 3 led to ethyl 4-oxobutanoate 4. In the presence of pyruvate,... 

While in the presence of 2-oxoglutaric acid neither decarboxylation nor acyloin condensation had been observed, as expected from previously published results (75), we succeeded in the enzymatic conversion of the mono ethyl ester 3 to ethyl 4-oxobutanoate 4, using both whole yeast cells (Saccharomyces cerevisiae) and purified PDC. The oxo ester 4 served as substrate for a second reaction catalyzed by PDC. Formation of a new carbon-carbon bond was accomplished in the presence of pyruvic acid which acted as donor of a C2-unit. Thus, ethyl 4-hydroxy-5-oxohexanoate 5 was obtained for the first time as the result of an enzymatic acyloin condensation. Finally, traces of acid induced the lactonization of hydroxyester 5, indicating it as direct precursor of solerone 1 (Figure 1). 

The biogenesis of solerone 1 and related compounds was successfully rationalized by biomimetic model reactions. As key step we established the pyruvate decarboxylase catalyzed acyloin condensation of pyruvic acid with ethyl 4-oxobutanoate 4 or ethyl 2-oxoglutarate 3 with acetaldehyde. The importance of the ethyl ester function in 3 and 4 serving as substrates for the enzymatic formation of a-hydroxy ketones 5 and 6 was demonstrated. The identification of six yet unknown sherry compounds including acyloins 5 and 6, which have been synthesized for the first time, confirmed the relevance of the biosynthetic pathway. Application of MDGC-MS allowed the enantiodifferentiation of a-ketols and related lactones in complex sherry samples and disclosed details of their biogenetic relationship. 

The (S)-enzyme (relative molecular mass 48000 -50000) reduced 3-oxoacid esters, 4-oxo and 5-oxoacids and esters enantioselectively to (S)-hydroxy compounds. The K -values for ethyl 3-oxobutanoate, ethyl 3-oxohexanoate, 4-oxopentanoic acid and 5-oxohexanoic acid were determined as 0.9 mM, 5.3 mM, 17.1 mM and 13.1 mM, respectively. 

FCC) ETHYL ACETYLACETONATE ETHYL BENZYL ACETOACETATE ETHYL-3-OXO-BUTANOATE ETHYL-3-OXOBUTYRATE FEMA No. 2415 3-OXOBUTANOIC ACID ETHYL ESTER... 

OXO-BUTANOIC ACID BUTYL ESTER see BPV250 3-OXOBUTANOIC ACID ETHYL ESTER see EFSOOO 3-OXOBUTANOIC ACID METHYL ESTER see MFX250 Y-OXO-a-BUTYLENE see BOY500... 

MCI-186, has been developed as a medical drug for brain ischemia. The preparation of pyrazol-3-ones 57a-m was achieved by refluxing /i-keto esters 56a-m and hydrazines 2a-m in ethanol or acetic acid. /i-Keto esters 56d,e,j,l,m, which are not commercially available, were synthesized from acyl chlorides 52a,b, nitrile 53 or ethyl esters 55a,b with the appropriate reagents (Scheme 13). Ethyl 2-acetyl-3-methylbut-3-enoate 56k was prepared in 43% yield from ethyl 3-oxobutanoate 56a by first forming ethyl 3-oxobutanoate sodium salt and then treating the salt with isobutyl iodide in THF at 80 °C. 

Baker s yeast reduction of methyl 2-(l,3-dithian-2-yl)-3-oxobutanoate gives the syn-configurated methyl (2R,3S)-2-(l,3-dithian-2-yl)-3-hydroxybutanoate in 42% yield and high diastereo- and enantioselectivity (92% de, >99% ee)225. Reduction of the ethyl ester shows a similar selectivity with a chemical yield of 62%. 

F.52) Butanoic acid, 3-oxo-, ethyl ester, ethyl acetoacetate, ethyl 3-oxobutanoate, ethyl acetylacetate, acetoacetic acid ethyl ester, diacetic ether (1-41-97-9] FEMA 2415... 

OXOBUTANOIC ACID ETHYL ESTER (141-97-9) CjHioOj Forms explosive mixture with air [explosion limits in air (vol %) 1.4 to 9.5 flash point 135°F/57°C autoignition temp 563°F/295°C Fire Rating 3]. Violent... 

CH3C—CH2—COC2H5 ethyl 3-oxobutanoate ethyl acetoacetate "acetoacetic ester"... 

The second classical reaction mentioned above is the acetoacetic ester synthesis. this reaction, an ester of acetoacetic acid (3-oxobutanoic acid) such as ethyl acetoacetate is treated with base under thermodynamic control conditions and alkylated, as with the malonic ester synthesis. Reaction with sodium ethoxide in ethanol (since an ethyl ester is being used) generated the enolate and quenching with benzyl bromide led to 84. Saponification and decarboxylation (as above) gave a substituted ketone (85). Although the malonic ester synthesis and the acetoacetic ester synthesis are fundamentally similar, the different substrates lead to formation of either a highly substituted acid or a ketone. The reaction is not restricted to acetoacetate derivatives, and any p-keto-ester can be used (ethyl 3-oxopentanoate for example). ... 

Synonyms Acetoacetic acid ethyl ester Acetoacetic ester Diacetic ether Diacetyl ether EAA EEA Ethyl acetyl acetate Ethyl acelylacetonate Ethyl benzyl acetoacetate Ethyl 3-oxobutanoate Ethyl 3-oxobulyrate 3-Oxobutanoic acid ethyl ester Classification Aliphatic organic compd. 

Oxobutanoic acid ethyl ester. See Ethylacetoacetate a-Oxodiphenylmethane. See Benzophenone... 

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