Elaidic acid

C8Hi7CH=CH(CH2)7COOH Elaidic acid frans-9-Octadecenoic acid... 

Alkenoic acids also have polymorphic crystalline forms. For example, both oleic and elaidic acids are dimorphic with melting points of 13.6 and 16.3°C for oleic, and 43.7 and 44.8°C for elaidic acid (14). 

Other alkenoic acids that have been dimerized with retention of configuration at the double bond are oleic acid (23 % dimer yield), elaidic acid (44%) [143], and erucic acid (40%) [144]. 

The carbon chains of samrated fatty acids form a zigzag pattern when extended, as at low temperamres. At higher temperatures, some bonds rotate, causing chain shortening, which explains why biomembranes become thinner with increases in temperamre. A type of geometric isomerism occurs in unsaturated fatty acids, depending on the orientation of atoms or groups around the axes of double bonds, which do not allow rotation. If the acyl chains are on the same side of the bond, it is cis-, as in oleic acid if on opposite sides, it is tram-, as in elaidic acid, the tram isomer of oleic acid (Fig-... 

Figure 14-5. Geometric isomerism of A , 18 1 fatty acids (oleic and elaidic acids).

This stearolic acid has been thoroughly characterized 3 6 by the freezing-point curve, ultraviolet and infrared spectra, ozonization, and hydrogenation. It has been shown to be free both of positional isomers and of olefinic acids such as oleic and elaidic acids. Its properties include m.p. 46-46.5°, iodine number (Wijs titration, 30 minutes) 89.5, d 5 1.4510, d 5 1.4484, neutral equivalent 279.2-279.6 (theory 280.4), hydrogen uptake 95-100% of theory for a triple bond. The last trace of color is difficult to remove by recrystallization from petroleum ether. It can be removed, however, by crystallization from a 20-30% solution in acetone at —5 to —8°, or from an 8-10% solution at —20°, or by distillation (b.p. 189-190°/2mm.). 

Eicosene, i2 Elaidic acid, oil Enanthic alcohol, hll Enanthylic acid, h9 Epibromohydrin, b328 Epichlorohydrine, cl20 1,4-Epoxybutane, t69... 

Ekato Intermig agitator, 1 739, 740 Ekoflot pneumatic cell, 16 653 Elaidic acid, physical properties,... 

The immobilized enzymes can, therefore, be easily separated by filtration and they are recyclable several times without loss of activity. Actually, total turnovers as high as 2 x 105 moles of product per mole of catalyst have been recorded. Nevertheless, as a drawback, it is worth highlighting that these systems are very sensitive to the kind of substrate employed and hence they can be unsuitable and less versatile for some particular oleochemical applications. For instance, fatty compounds with the C=C in the trans configuration, such as elaidic acid, react very slowly, and the epoxidation of polyunsaturated oleochemicals proceeds step by step. This means that the formation of di-epoxides takes place only after the nearly complete formation of monoepoxides. 

N4. Nestel, P., Noakes, M., Belling, B., McArthur, R., Clifton, P., Janus, E., and Abbey, M., Plasma lipoprotein lipid and Lp(a) changes with substitution of elaidic acid for oleic acid in the diet. J. Lipid Res. 33, 1029-1036 (1992). 

This arrangement is also similar to that adopted by the headgroups of long chain aliphatic acids in LB films. Intercalation at over 100% AFC was shown to be a result of co-intercalation of sodium cations or neutral stearic acid molecules. In the case of tra 5-CH3(CH2)7CH = CH(CH2)7COOH (elaidic acid), two different intercalated LDHs with a monolayer of elaidate anions... 

Fig. 25 Proposed packing arrangements in LDHs intercalated with a monolayer of elaidate anions (on the /e/f), a mixed bilayer of elaidate anions and neutral elaidic acid molecules (center) and oleate anions (on the right). Reprinted with permission from [216]. Copyright American Chemical Society...

Ci6j Cjg saturated fatty acids, Armak Industrial Chemicals Division (Chicago, IL) oleic acid, A. Gross Company (Newark, NJ) elaidic acid, laboratory preparation (12) tallow, Corenco Corporation (Philadelphia, PA) (titer, t =... 

Figure 11.10 Structure of ds-octadecenoic and trans-octadecenoic add (an example o/cis-trans isomerism). The common name for trans-octadecenoic acid is elaidic acid it is one of the few naturally occurring trans fatty acids. The common name for c/s-octadecenoic acid is oleic acid. Note that the two hydrocarbon chains are separated by the double bond which prevents rotation of the position of the two chains. The structure of the trans fatty acid is biochemically unusual and therefore biochemically excluded. ...

Elaidic acid (m.p., 41-43°), prepared by nitrogen oxides elaidiniza-tion of oleic acid, gave an ethyl ester (m.p., 3-5°C. nD25, 1.4476). 

Oxidation of Elaidic Acid Ozonization Products. Elaidic acid was ozonized in chloroform solution (5.0 grams in 100 ml.) at 0°C., and the solvent was removed by rotatory evaporation at room temperature. Aliquots were oxidized catalytically and noncatalytically as described above. 

Oxidation of Elaidic Acid Ozonization Products. Aliquots of the unseparated ozonization products from elaidic acid were autoxidized at 95 °C. uncatalyzed and in acetone over reduced platinum oxide as before. Total yields of acids and esters were determined by titration and were found to be 74.6 and 19.2%, respectively, in the catalyzed reaction with uptake of 63% of the theoretical volume of oxygen. Time required for uptake of half this volume was 4 hours at 21 °C. Uncatalyzed oxidation at 95°C. of the other fraction gave 27.4% yield of esters and 74.5% yield of acids, calculated on the assumption that one original olefinic linkage can produce one ester function or two acid functions. When elaidic acid was ozonized in methyl acetate and the catalyzed oxidation performed in the same solvent, acid yield was 80.8%, and ester yield was 7.3% with a half-uptake time of 5.6 hours and 88% of the theoretical quantity of... 

Elaidic acid [112-79-8] M 282.5, m 44.5°. Crystd from acetic acid, then EtOH. 

Elaidic acid, 39, IS Electrolytic apparatus, 36, 22 Electrolytic reduction of o chloromtro-benzene, 35, 23... 

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