Syntheses of conjugated octadecadienoic acids

Kellersmann, Carolin; Steinhart, Hans; Francke, Wittko

doi:10.1007/s11745-006-5031-8

Cited by 5 publications

(4 citation statements)

References 24 publications

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“…In contrast to these reactions, cross‐coupling reactions between sp 3 ‐hybridized carbon centers5 appear to be a useful and, potentially, more‐promising tool, because they are applicable to the synthesis of both saturated and unsaturated fatty acids and they are free from the problems associated with double‐bond stereochemistry 6–8. However, owing to the lower tolerance of the carboxylic group toward organometallic reagents, including transition‐metal complexes,9, 10 protected carboxy groups3c, 4b, 8, 11 or their synthetic equivalents3a,d, 4c are often employed. Herein, we report a convenient and efficient one‐pot procedure for the construction of carbon frameworks of fatty acids by using the nickel‐catalyzed cross‐coupling of alkyl halides that contain a carboxy functionality with Grignard reagents in the presence of 1,3‐butadiene as an additive,8e, 12, 13 in combination with an in situ protection procedure 14.…”

Section: Methodsmentioning

confidence: 99%

NickelButadiene Catalytic System for the Cross‐Coupling of Bromoalkanoic Acids with Alkyl Grignard Reagents: A Practical and Versatile Method for Preparing Fatty Acids

Iwasaki

Higashikawa

Reddy

et al. 2013

Chemistry A European J

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Section: Methodsmentioning

confidence: 99%

NickelButadiene Catalytic System for the Cross‐Coupling of Bromoalkanoic Acids with Alkyl Grignard Reagents: A Practical and Versatile Method for Preparing Fatty Acids

Iwasaki

Higashikawa

Reddy

et al. 2013

Chemistry A European J

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“…Conjugated linoleic acids (CLAs) have been extensively investigated using 1 H-NMR ( Table 4 ) including the ( cis -9, trans -12) 18:2 isomer, which is the dominant species in dairy products, and several other positional and geometric isomers [ 55 , 56 ] which may have different biological functions. Figure 5 illustrates that the 1 H-NMR spectrum of CLAs in the lipid fraction of milk exhibit highly diagnostic resonances due to the –C H = protons of the conjugated double bonds in the region of 6.35 to 5.50 ppm.…”

Section: Nmr Structural and Analytical Parametersmentioning

confidence: 99%

High Resolution NMR Spectroscopy as a Structural and Analytical Tool for Unsaturated Lipids in Solution

et al. 2017

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Mono- and polyunsaturated lipids are widely distributed in Nature, and are structurally and functionally a diverse class of molecules with a variety of physicochemical, biological, medicinal and nutritional properties. High resolution NMR spectroscopic techniques including 1H-, 13C- and 31P-NMR have been successfully employed as a structural and analytical tool for unsaturated lipids. The objective of this review article is to provide: (i) an overview of the critical 1H-, 13C- and 31P-NMR parameters for structural and analytical investigations; (ii) an overview of various 1D and 2D NMR techniques that have been used for resonance assignments; (iii) selected analytical and structural studies with emphasis in the identification of major and minor unsaturated fatty acids in complex lipid extracts without the need for the isolation of the individual components; (iv) selected investigations of oxidation products of lipids; (v) applications in the emerging field of lipidomics; (vi) studies of protein-lipid interactions at a molecular level; (vii) practical considerations and (viii) an overview of future developments in the field.

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“…Conjugated linoleic acids (CLAs) have been extensively investigated using 1 H- and 13 C-NMR [ 6 , 18 , 19 , 20 , 21 , 22 ]. NOESY experiments, and the analyses of spin–spin coupling constants were utilized to identify the geometric configurations of the double bonds [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

DFT Calculations of 1H- and 13C-NMR Chemical Shifts of Geometric Isomers of Conjugated Linoleic Acid (18:2 ω-7) and Model Compounds in Solution

et al. 2020

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A density functional theory (DFT) study of the 1H- and 13C-NMR chemical shifts of the geometric isomers of 18:2 ω-7 conjugated linoleic acid (CLA) and nine model compounds is presented, using five functionals and two basis sets. The results are compared with available experimental data from solution high resolution nuclear magnetic resonance (NMR). The experimental 1H chemical shifts exhibit highly diagnostic resonances due to the olefinic protons of the conjugated double bonds. The “inside” olefinic protons of the conjugated double bonds are deshielded than those of the “outside” protons. Furthermore, in the cis/trans isomers, the signals of the cis bonds are more deshielded than those of the trans bonds. These regularities of the experimental 1H chemical shifts of the olefinic protons of the conjugated double bonds are reproduced very accurately for the lowest energy DFT optimized single conformer, for all functionals and basis sets used. The other low energy conformers have negligible effects on the computational 1H-NMR chemical shifts. We conclude that proton NMR chemical shifts are more discriminating than carbon, and DFT calculations can provide a valuable tool for (i) the accurate prediction of 1H-NMR chemical shifts even with less demanding functionals and basis sets; (ii) the unequivocal identification of geometric isomerism of CLAs that occur in nature, and (iii) to derive high resolution structures in solution.

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Syntheses of conjugated octadecadienoic acids

Cited by 5 publications

References 24 publications

NickelButadiene Catalytic System for the Cross‐Coupling of Bromoalkanoic Acids with Alkyl Grignard Reagents: A Practical and Versatile Method for Preparing Fatty Acids

NickelButadiene Catalytic System for the Cross‐Coupling of Bromoalkanoic Acids with Alkyl Grignard Reagents: A Practical and Versatile Method for Preparing Fatty Acids

High Resolution NMR Spectroscopy as a Structural and Analytical Tool for Unsaturated Lipids in Solution

DFT Calculations of 1H- and 13C-NMR Chemical Shifts of Geometric Isomers of Conjugated Linoleic Acid (18:2 ω-7) and Model Compounds in Solution

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