13126-43-7Relevant articles and documents
A Facile and Efficient Method for the Synthesis of Labeled and Unlabeled Very Long Chain Polyunsaturated Fatty Acids
Hamberg, Mats
, p. 489 - 494 (2021/04/19)
Several methods are available for elongation of fatty acid acyl chains. The present paper describes adaptation to the fatty acid field of a previously published protocol for manganese-based Wurtz type coupling of alkyl bromides. 22-Bromo-3(Z),6(Z),9(Z),12(Z),15(Z),18(Z)-docosahexaene, easily prepared from 4(Z),7(Z),10(Z),13(Z),16(Z),19(Z)-docosahexaenoic acid, was coupled to homologous ω-bromoesters by stirring for 4 hours at 40°C in the presence of manganese powder, a nickel catalyst and terpyridine. This afforded in yields of 70–75% a series of ω3-hexaenoates of chain lengths of 32–40 carbons. The corresponding fatty acids of >98% purity were obtained following saponification and final purification. By using methyl [2,2,3,3,4,4-2H6]10-bromodecanoate as coupling partner it was possible to prepare a very long chain fatty acid in isotopically labeled form, i.e., [2,2,3,3,4,4-2H6]14(Z),17(Z),20(Z),23(Z),26(Z),29(Z)-dotriacontahexaenoic acid. Also prepared were the monounsaturated long chain fatty acids 15(Z)-octadecenoic acid and 15(Z)-tetracosenoic acid. Very long chain fatty acids have been isolated from retina and other tissues and are of biological relevance. The methodology described will assist in further analytical and biological studies in this field.
Facile and stereoselective synthesis of (Z)-15-octadecenoic acid and (Z)-16-nonadecenoic acid: Monounsaturated omega-3 fatty acids
Rawling, Tristan,Duke, Colin C.,Cui, Pei H.,Murray, Michael
experimental part, p. 159 - 165 (2010/08/05)
Facile syntheses of the monounsaturated omega-3 fatty acids, (Z)-15-octadecenoic acid and (Z)-16-nonadecenoic acid, are presented. Commercially available hydroxy fatty acids were esterified and oxidised, followed by the Wittig reaction to introduce the omega-3 olefinic bond; hydrolysis yielded the omega-3 fatty acids in high purity. An examination of different reaction conditions for the Wittig step found that THF as solvent and coupling temperatures of -78 °C gave optimal stereoselectivity, affording the omega-3 olefins in Z:E ratios 97:3. The syntheses have overall yields of ~43%, and utilise straightforward, robust chemistry, that may be readily scaled up and reproduced. Also presented is a method for accurately determining the double bond geometry and isomeric purity of the fatty acid products using 1H-13C-HSQC NMR and GC-MS, respectively.
