6828. Oleic Acid

Nomenclature

CAS number: 112-80-1
(Z)-9-Octadecenoic acid.
C18H34O2; mol wt 282.46.
C 76.54%, H 12.13%, O 11.33%.

Description and references

Obtained by the hydrolysis of various animal and vegetable fats and oils. Prepn from olive oil: Biochem. Prep. 2, 100 (1952). Separation from olive oil by double fractionation via urea adducts: Rubin, Paisley, Biochem. Prep. 9, 113 (1962). Stereochemistry: Thieme, Ann. 343, 354 (1905). Synthesis: Robinson, Robinson, J. Chem. Soc. 127, 175 (1925). 13C-NMR studies: W. Stoffel et al., Z. Physiol. Chem. 353, 1962 (1972); J. G. Batchelor et al., J. Org. Chem. 39, 1698 (1974). Toxicity data: L. Or"o, A. Wretlind, Acta Pharmacol. Toxicol. 18, 141 (1961). Exptl use of 131I-labelled oleic acid in myocardial imaging: F. J. Bonte et al., Radiology 108, 195 (1973). Review of diagnostic use of 3H-oleic acid in pancreatic function: N. T. Pedersen, Digestion 37, Suppl. 1, 25-34 (1987).

Chemical structure

Properties

Pure oleic acid is a colorless or nearly colorless liquid (above 5-7°). d2525 ≈0.895. Solidifies to cryst mass, mp 4°. bp100 286°. At atm pressure it dec when heated at 80-100°. nD18 1.463; nD26 1.4585. Iodine no. 89.9; acid value 198.6. On exposure to air, especially when impure, it oxidizes and acquires a yellow to brown color and rancid odor. Practically insol in water. Sol in alcohol, benzene, chloroform, ether, fixed and volatile oils. Keep well closed, protected from light. LD50 i.v. in mice: 230±18 mg/kg (Or"o, Wretlind). Several grades of the acid are available in commerce, varying in color from pale yellow to red-brown and, depending on the amount of saturated acid present, becoming turbid at 8-16°. The acid of commerce usually contains 7-12% saturated acids, e.g., stearic, palmitic; also some linoleic, etc., unsaturated acids.

Derivative

Methyl ester.

Nomenclature

Methyl oleate.
C19H36O2; mol wt 296.49.
C 76.97%, H 12.24%, O 10.79%.

Description and references

Prepd by refluxing oleic acid with p-toluene sulfonic acid in methanol: Rubin, Paisley, loc. cit. Iodine no. 85.6.

Properties

d418 0.879. nD26 1.4510. bp2 168-170°. Miscible with anhydr ethanol, ether.

Derivative

Ethyl ester.

Nomenclature

Ethyl oleate; (Z)-9-octadecenoic acid ethyl ester.
C20H38O2; mol wt 310.51.
C 77.36%, H 12.34%, O 10.31%.

Properties

Yellowish, oily liquid. d 0.87. bp 205-208° (some dec). Insol in water. Misc with alcohol, ether.

Derivative

Barium salt.

Nomenclature

Barium oleate.
C36H66BaO4; mol wt 700.23.
C 61.75%, H 9.50%, Ba 19.61%, O 9.14%.

Properties

Yellowish-white, granular masses. Poisonous. Practically insol in water. Slightly sol in boiling alcohol.

Derivative

Sodium salt.

Nomenclature

CAS number: 143-19-1
Eunatrol.
C18H33NaO2; mol wt 304.44.
C 71.01%, H 10.93%, Na 7.55%, O 10.51%.

Properties

White powder, slight tallow-like odor. Sol in ≈10 parts water, ≈20 parts alcohol. Generally contains small quantities of the sodium salts of stearic, etc. acids. Alkaline in aq solns due to hydrolysis but not in alcohol solns.

Caution

Mildly irritating to skin, mucous membranes.

Use

Prepn of Turkey red oil, soft soap and other oleates; in polishing compds; waterproofing textiles, oiling wool; manuf driers; thickening lubricating oils. Pharmaceutic aid (solvent). The barium salt in rodent extermination.

Therapeutic Category

Diagnostic aid (pancreatic function).

Keywords

Diagnostic Aid