Fatty acids fluorinated

A/-Chloro fatty acid amides have been synthesized from the direct halogenation of the amide in boiling water (28). They are useful as reactive intermediates for further synthesis. Fluorination has also been reported by treating the fatty amide with fluorine-containing acid reagents at 200 °C to reach a fluorinated amide with less reactivity toward fluorocarbon polymers (29). 

Release agents function by either lessening intermolecular interactions between the two surfaces in contact or preventing such close contact. Thus, they can be low surface-tension materials based on aUphatic hydrocarbon, fluorocarbon groups, or particulate soHds. The principal categories of material used are waxes, fatty acid metal soaps, other long-chain alkyl derivatives, polymers, and fluorinated compounds. 

Saturable dye absorber, 14 677 Saturated aqueous salt solution, 9 34 Saturated calomel electrode (SCE), 9 571 Saturated fatty acids, 10 829, 830 Saturated hydrocarbons adsorbent affinity, 1 674 adsorption by zeolites, 1 624 fluorine reactivity with, 11 831 isomerization of, 12 172—173 Saturated polyester resins, based on trimethylpentanediol, 12 673 Saturated polyesters, 10 7 Saturated synthetic rubber, 10 705 Saturation and coating processes, 10 12-13 Saturation bonding, 17 509-510 Saturation color, 19 262 Saturation concentration, 15 677 Saturation index... 

Chenoweth believes that an explanation of the above results may lie in the reactions occurring before the entrance of fatty acid metabolites into the citric acid cycle. Activated acetate, i.e. acetyl coenzyme A (AcCoA) is the end-product of fatty acid metabolism prior to its condensation with oxalacetate to form citrate. Possibly fluoro-fatty acids behave like non-fluorinated fatty acids. The end-product before the oxalacetate condensation could be the same for all three fluorinated inhibitors, viz. fluoroacetyl coenzyme A (FAcCoA). Fluorocitrate could then be formed by the condensation of oxalacetate with FAcCoA, thereby blocking the citric acid cycle. The specificity of antagonisms must therefore occur before entrance of the metabolites into the citric acid cycle. 

N. R. Simpson, S.M. Larson, Synthesis of a fluorinated fatty acid, dl-erythro-9,10-[ F]difluoropalmitic acid, and biodistribution in rats, Nucl. Med. Biol. 17 (1990) 805-809. 

M.T. Maki, M. Haaparanta, P. Nuutila, V. Oikonen, M. Luotolahti, O. Eskola, J.M. Knuuti, Free fatty acid uptake in the myocardium and skeletal muscle using fluorine-18-fluoro-6-thia heptadecanoic acid, J. Nucl. Med. 39 (1998) 1320-1327. 

Fluorine is found in nature as mineral fluorides, and it is the most abundant halogen in the Earth s crust. Thus, it is rather surprising that less than 15 fluorinated organic molecules have been isolated from plants. They are aU secondary metabolites of fluoroacetate. Among these compounds, all monofluorinated, half are composed of (w-fluorinated homologues of fatty acids. ... 

Mono-, di-, and trifluoro derivatives of fatty acids have been prepared in regio- and stereoselective manners, in order to evaluate the gauche effect induced by fluorine atoms on the conformation of hydrocarbon chains and for enzymatic studies. 

Because the forces of attraction prevail when molecules are brought into sufficiently dose proximity under normal conditions, release is best effected if both the strength of the interaction and the degree of contact are minimized. Aliphatic hydrocarbons and fluorocarbons achieve the former effect, finely divided solids the latter. Materials such as microcrystalline wax [64742 42-3] and hydrophobic silica [7631-86-9] combine both effects. Some authors refer to this combined effect as the ball bearing mechanism. A perfluoroalkylated fullerene nanosphere would perhaps be the ultimate example of this combined effect (17). These very general mechanistic remarks can be supplemented by publications on the mechanism of specific classes of release agents such as metallic stearates (18), fatty acids and fluorinated compounds (19), and silicone-coated rdease papers (20,21). The mechanism of release of certain problem adherents, eg, polyurethanes, has also been addressed (22,23). 

Interest centers on fluoroacetic acid itself,54-55,56 115 but its monofluorinated homologs have been equally studied to attempt to verify the observation that only compounds CFH2(CH2)nC02H with n = 0 or even numbers, and their derivatives (esters, salts) show considerable toxicity (Table 11) in addition to that of their acid function. In the course of in vivo metabolism these fluorinated derivatives end up, like any fatty acid by /(-oxidation or hydrolysis, as the toxic fluoroacetic acid. With an uneven number of n, metabolism stops at the stage of the less toxic 2-fluoropropanoic acid (CFH2CH2C02H). 

The infamous fluoroacetic acid and the equally toxic naturally occurring even-numbered co-fhiorinated fatty acids were discussed in detail earlier (7), and several reviews are available (34,44, 66). Although not counted as being natural in the earlier survey (7), 4-fluorothreonine (837) is now considered to be a bona fide natural metabolite of Streptomyces cattleya (893), the stereochemistry of which has been confirmed by synthesis (894). In addition to the five oo-fluorinated fatty acids presented earlier (7), new studies of the seed oil of Dichapetalum toxicarium have uncovered 16-fluoro-palmitoleic acid (838), 18-fluorostearic acid (839), 18-fluorolinoleic acid (840), 20-fluoroarachidic acid (841), 20-fluoroeicosenoic acid (842), 18-fluoro-9,10-epoxystearic acid (843) (895), (Z)-16-fluorohexadec-7-enoic acid (844), (Z)-18-fluoroocta-dec-9-enoic acid (845), and (Z)-20-fluoroicos-9-enoic acid (846) (896). 

Christie WW, Hamilton JTG, Harper DB (1998) Mass Spectrometry of Fluorinated Fatty Acids in the Seed Oil of Dichapetalum toxicarium. Chem Phys Lipids 97 41... 

Among esters of sucrose, some derivatives of fluorinated fatty acids have been prepared for evaluation as surfactants specifically designed for fluorocarbons containing emulsions used for biomedical applications, notably as blood substitutes.98,402 Some sucrose aspartate surfactants have been described.403... 

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