Esters of Fatty Acids
Esters are chemical compounds derived formally from an oxoacid (one containing an oxo group, X=O), and a hydroxyl compound such as an alcohol or phenol. Esters consist of an inorganic acid or organic acid in which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group. They are analogous to salts, using organic alcohols instead of metallic hydroxides. Esters are ubiquitous. Many naturally occurring fats and oils are the fatty acid esters of glycerol. Esters with low molecular weight are commonly used as fragrances and found in essential oils and pheromones. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties, while polyesters are important plastics, with monomers linked by ester moieties. Some acids that are commonly esterified are carboxylic acids, phosphoric acid, sulfuric acid, nitric acid, and boric acid. Cyclic esters are called lactones. The preparation of an ester is known generally as an esterification reaction. This article will deal primarily with the esters derived from carboxylic acids and alcohols, the most common type of esters.