171087-45-9Relevant academic research and scientific papers
A divergent synthesis of [1-14C]-mono-E isomers of fatty acids
Georgin,Taran,Mioskowski
, p. 83 - 91 (2007/10/03)
A convenient synthesis of [1-14C]-mono-trans fatty acid using olefin inversion as a key-step is described. This methodology allows for a facile synthesis of [1-14C]-labelled mono-trans analogues of oleic, linoleic and linolenic acids. As an example, only eleven steps were necessary to obtain the [1-14C]-mono-E isomers of linolenic acid from its commercial all-Z form. In the first step, Barton's decarboxylation procedure yielded a bromo intermediate. Epoxidation of this compound resulted in the formation of three monoepoxides, which could be separated by HPLC. After identification by 1H NMR and MS, the pure monoepoxides were then subjected to inversion consisting of a stereospecific deoxygenation followed by a β-elimination step. Finally, the labelling was introduced by substitution of the bromine by a [14C]-cyano group followed by hydrolysis.
Large-scale preparation of (9Z,12E)-[1-13C]-octadeca-9,12-dienoic acid, (9Z,12Z,15E)-[1-13C]-octadeca-9,12,15-trienoic acid and their [1-13C] all-cis isomers
Loreau,Maret,Poullain,Chardigny,Sebedio,Beaufrere,Noel
, p. 65 - 78 (2007/10/03)
Several grams of labelled trans linoleic and linolenic acids with high chemical and isomeric purities (>97%) have been prepared for human metabolism studies. A total of 12.5 g of (9Z,12E)-[1-13C]-octadeca-9,12-dienoic acid and 6.3 g of (9Z,12Z,15E)-[1-13C]-octadeca-9,12,15-trienoic acid were obtained in, respectively, seven steps (7.8% overall yield) and 11 steps (7% overall yield) from 7-bromo-heptan-1-ol. The trans bromo precursors used for the labelling were synthesised by using copper-catalysed couplings. The trans fatty acids were then obtained via the nitrile derivatives. A total of 23.5 g of (9Z,12Z)-[1-13C]-octadeca-9,12-dienoic acid and 10.4 g of (9Z,12Z,15Z)-[1-13C]-octadeca-9,12,15-trienoic acid were prepared in five steps in, respectively, 32 and 18% overall yield. Large quantities of bromo and chloro precursors were synthesised from the commercially available acid according to Barton's procedure. In all cases, the main impurities (>0.5%) of each labelled fatty acid have been characterised. Copyright (C) 2000 Elsevier Science Ireland Ltd.
Synthesis of (9Z,12E)- and (9E,12Z)-[1-14C]linoleic acid and (5Z,8Z,11Z,14E)-[1-14C]arachidonic acid
Berdeaux,Vatele,Eynard,Nour,Poullain,Noel,Sebedio
, p. 71 - 80 (2007/10/03)
(3Z,6E)-1-Bromododeca-3,6-diene, a common intermediate in the synthesis of labelled 12t linoleic acid and 14t arachidonic acid, was obtained from (E)-3-nonyl-1-ol: in four steps, via conventional functional manipulations. Cross-coupling of this bromododecadiene with the Grignard reagent of 1-chloro-5-(tetrahydropyranyloxy)pentane gave a C17 dienic ether which was further transformed in three steps to 12t-[l-14C]linoleic acid in 22% overall yield from 3-nonyl-1-ol (eight steps). The synthesis of 14t arachidonic acid involves a Wittig reaction between (Z)-7-(t-butyldiphenylsilyloxy)hept-3-enal and the ylide of (3Z,6E)-dodeca-3,6-dienyl-triphenylphosphonium bromide. The resulting C19 tetraenic ether was transformed in three steps to 14t [l-14C]arachidonic acid (isomeric and radiochemical purities > 99%). 9t Linoleic acid was obtained by a stepwise six-carbon elongation chain of both ends of(E)-6-(2-tetrahydropyranyloxy)-hex-3-enyltriphenylphosphonium salt in 20% overall yield.
