Hydroxybutyric acid

Hydroxybutyric acid is a group of four-carbon organic compounds that have both hydroxyl and carboxylic acid functional groups. They can be viewed as derivatives of butyric acid. The carboxylate anion and the esters of hydroxybutyric acids are known as hydroxybutyrates.

There are three isomers, distinguished by the distance between the two functional groups:


 * alpha-Hydroxybutyric acid (2-hydroxybutyric acid)
 * beta-Hydroxybutyric acid (3-hydroxybutyric acid)
 * gamma-Hydroxybutyric acid (4-hydroxybutyric acid, GHB)