Branched-chain fatty acids. XXV. Methods of synthesis of 2-alkenoic acids

Cason, James; Allinger, Norman L.; Sumrell, Gene

doi:10.1021/jo50013a012

Cited by 39 publications

(12 citation statements)

References 8 publications

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“…Subsequent B,pelimination then leads to the formation of the A3 isomer as an artifact. The direct equilibration of 2-and 3-alkenoic esters by heating in 10% KOH solution has also been observed (CASON et a/., 1953). It might be noted that similar artifacts have been reported to occur with non-conjugated unsaturated acids when a BF,-methanol system is employed for methylation (FULK & SHOUB, 1970;COOK & SPENCE, 1974).…”

Section: 15mentioning

confidence: 67%

THE ACTIVITY OF PARTIAL REACTIONS IN THE CHAIN ELONGATION OF PALMITOYL‐CoA AND STEAROYL‐CoA BY MOUSE BRAIN MICROSOMES

Bernert

Bourre

Baumann

et al. 1979

Journal of Neurochemistry

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Partial reactions in the overall chain elongation of palmitoyl‐CoA and stearoyl‐CoA by mouse brain microsomes have been analyzed. The rate of the initial condensation reaction between palmitoyl‐CoA and malonyl‐CoA was more than 5 times greater than the rate obtained with stearoyl‐CoA, and in both cases good agreement between condensation and overall chain elongation rates was observed. By contrast, both β‐hydroxyoctadecanoyl‐CoA and β‐hydroxyeicosanoyl‐CoA were quite rapidly dehydrated by brain microsomes at similar rates. Similar results were obtained with 2‐trans‐octadecenoyl‐CoA and 2‐trans‐eicosenoyl‐CoA in which both substrates were rapidly reduced at nearly the same rate in the presence of NADPH. In all cases, intermediate reactions subsequent to condensation were much more rapid than overall chain elongation. These results suggest that the mechanism of malonyl‐CoA‐dependent fatty acid chain elongation in brain microsomes is similar to that observed in other tissues, and are consistent with an overall regulation of chain elongation mediated primarily by the initial condensation reaction.

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Section: 15mentioning

confidence: 67%

THE ACTIVITY OF PARTIAL REACTIONS IN THE CHAIN ELONGATION OF PALMITOYL‐CoA AND STEAROYL‐CoA BY MOUSE BRAIN MICROSOMES

Bernert

Bourre

Baumann

et al. 1979

Journal of Neurochemistry

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“…3-Methylnonanamide was prepared from 3-methylnonanoic acid (24) by the procedure used for -methylcaprylamide; yield of crude amide, 96%. A sample crystallized three times from acetone-water had m.p.…”

Section: -81°]mentioning

confidence: 99%

The Preparation of β-Keto Esters from Nitriles and α-Bromoesters

Cason¹,

Rinehart²,

Thornton³

1953

J. Org. Chem.

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“…6, regarded as the purest sample of unsaturated ester, showed absence of dienoic ester or non-conjugated unsaturated ester; «204 7,600, e2oe 10,000, 6218. 6 12,100 (max), «279 69. There was previously reported (10) for a 2-methyl ester <21» 12,200 (max).…”

Section: Experimental8mentioning

confidence: 99%

“…Found: N, 3.39. (-)-5-Methyl-2-tridecenoic acid -was prepared from 17 g. of the saturated acid by bromination and dehydrohalogenation with potassium teri-butoxide according to the procedure previously described (6) for synthesis of 5-methyl-2-hendecenoic acid, except that the product was fractionally distilled prior to purification by partial esterification.…”

Section: Experimental8mentioning

confidence: 99%

“…The only accurate absorption data available is that for methyl3-methyl-3-nonenoate (9), which has an e of about 1,600 at 210 µ. Since this compound has a methyl substituted at the double bond the curve is shifted to longer wavelengths by[5][6][7][8][9][10] µ; therefore 1000 is taken as the approximate value at 210 µ for the 3-alkenoic acid (or ester) not substituted on the double bond. The accuracy of this figure is adequate for present purposes, for the calculation is not very sensitive to it; if 1,600 be used, the content of 3-enoic acid is raised only to 38%.…”

mentioning

confidence: 99%

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Branched-chain fatty acids. XXVI. Synthesis of optically active acids of use in the study of the structure of C_27- phthienoic acid. Partial thermal racemization of (-)-5-methyl-2-tridecenoic acid

Cason¹,

Allinger²,

Allen³

1953

J. Org. Chem.

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In a previous paper of this series (1), the strongly dextrorotatory, physiologically active C27-phthienoic acid (2), isolated from the tubercle bacillus, was assigned a partial structure which included the features of a 2,5-dimethyl-2alkenoic acid. Although the position of the double bond and the 2-methyl seemed entirely unequivocal, assignment of the second methyl to the 5-position raised some points of dubiety which have now been further investigated. The assignment to the 5-position (formula I), rather than the 4-position (formula RCHCH2CH=CC02H R-CH2CHCH=CC02H CH, CH, CH3 CH, I II II), was made because heating of the C27-phthienoic acid gave only about 25% racemization, no more than about 5% lactone formation, and no observable equilibration of the double bond with the ß, -position. Since it has been reported8that heating of a 2-alkenoic acid containing a 4-methyl group promotes a high percentage of equilibration of the double bond with the ß, -position, followed by conversion of much of the acid to the -lactone, the behavior of C27-phthienoic acid seemed inconsistent with the presence of a 4-methyl group and resulted in assignment of the second methyl to the 5-position. This assignment can be validated, however, only if a 5-methyl-2-alkenoie acid is slowly racemized by thermal equilibration of the a, 5-unsaturation with the ß, -and , -positions, and if such an acid shows the high molecular rotation (73°) of C27-phthienoic acid.The present investigation has indicated that an a, /3-unsaturation may be thermally equilibrated as remotely as the , -position; however, the asymmetric center in the 5-position results in only a small optical rotation. Neither 5-methyl-2-tridecenoic acid (III) nor 2,5-dimethyl-2-tridecenoic acid (IV) has a molecular CsH17CHCH2CH=CHC02H CaH17CHCH2CH=C0 02H CH, CH, CH, III IV wt., 238, nf 1.

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Branched-chain fatty acids. XXV. Methods of synthesis of 2-alkenoic acids

Cited by 39 publications

References 8 publications

THE ACTIVITY OF PARTIAL REACTIONS IN THE CHAIN ELONGATION OF PALMITOYL‐CoA AND STEAROYL‐CoA BY MOUSE BRAIN MICROSOMES

THE ACTIVITY OF PARTIAL REACTIONS IN THE CHAIN ELONGATION OF PALMITOYL‐CoA AND STEAROYL‐CoA BY MOUSE BRAIN MICROSOMES

The Preparation of β-Keto Esters from Nitriles and α-Bromoesters

Branched-chain fatty acids. XXVI. Synthesis of optically active acids of use in the study of the structure of C_27- phthienoic acid. Partial thermal racemization of (-)-5-methyl-2-tridecenoic acid

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Branched-chain fatty acids. XXV. Methods of synthesis of 2-alkenoic acids

Cited by 39 publications

References 8 publications

THE ACTIVITY OF PARTIAL REACTIONS IN THE CHAIN ELONGATION OF PALMITOYL‐CoA AND STEAROYL‐CoA BY MOUSE BRAIN MICROSOMES

THE ACTIVITY OF PARTIAL REACTIONS IN THE CHAIN ELONGATION OF PALMITOYL‐CoA AND STEAROYL‐CoA BY MOUSE BRAIN MICROSOMES

The Preparation of β-Keto Esters from Nitriles and α-Bromoesters

Branched-chain fatty acids. XXVI. Synthesis of optically active acids of use in the study of the structure of C27- phthienoic acid. Partial thermal racemization of (-)-5-methyl-2-tridecenoic acid

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Branched-chain fatty acids. XXVI. Synthesis of optically active acids of use in the study of the structure of C_27- phthienoic acid. Partial thermal racemization of (-)-5-methyl-2-tridecenoic acid