W. Christie, R. Holman
Nov 1, 1967
Citations
1
Influential Citations
100
Citations
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Journal
Chemistry and Physics of Lipids
Abstract
Abstract The complete series of methylene-interrupted cis,cis -octadecadienoic acids (analogues of linoleic acid), from the 2,5- to 14,17-isomer, has been synthesized. The 4,7- to 10,13-isomers were prepared by coupling a 1-bromoalk-2-yne with the di-Grignard complex of an (ˑ)-acetylenic acid and semi-hydrogenation of the resulting diynoic acid to a cis,cis -diene with Lindlar's catalyst. The 2,5- and 3,6-isomers and the 11,14- to 14,17-isomers were synthesized by first preparing the corresponding diacetylenic alcohols which were then oxidized to the acids and semi-hydrogenated. Purity of the intermediates and final compounds was established by gas-liquid and thin-layer chromatography. The compounds were characterized by melting points, critical solution temperatures, infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance spectroscopy. Hydrogenation followed by gas chromatography confirmed the chain length and indicated absence of branched chain material. The positions of the double bonds were confirmed by ozonolysis. The 2,5-isomer has distinguishing features in its mass spectrum but only subtle distinctions can be detected in the spectra of the rest. The NMR spectra of the 2,5- to 5,8- and 11,14- to 14,17-isomers, however, all have features which uniquely identify them, though the 6,9- to 10,13-isomers have spectra which are virtually identical.