Enanthic acid, also called heptanoic acid, is an organic compound composed of a seven-carbon chain terminating in a carboxylic acid functional group. It is a colorless oily liquid with an unpleasant, rancid odor.[1] It contributes to the odor of some rancid oils. It is slightly soluble in water, but very soluble in ethanol and ether. Salts and esters of enanthic acid are called enanthates or heptanoates.
Its name derives from the Latinoenanthe which is in turn derived from the Ancient Greekoinos "wine" and anthos "blossom."
The methyl ester of ricinoleic acid, obtained from castor bean oil, is the main commercial precursor to enanthic acid. It is pyrolyzed to the methyl ester of 10-undecenoic acid and heptanal, which is then air-oxidized to the carboxylic acid. Approximately 20,000 tons were consumed in Europe and US in 1980.[2]
Laboratory preparations of enanthic acid include permanganate oxidation of heptanal[3] and 1-octene.[4]
^David J. Anneken, Sabine Both, Ralf Christoph, Georg Fieg, Udo Steinberner, Alfred Westfechtel "Fatty Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a10_245.pub2
^Donald G. Lee, Shannon E. Lamb, Victor S. Chang (1981). "Carboxylic Acids from the Oxidation of Terminal Alkenes by Permanganate: Nonadecanoic Acid". Organic Syntheses. 60: 11. doi:10.15227/orgsyn.060.0011.{{cite journal}}: CS1 maint: multiple names: authors list (link)