HOCHRCH2COO

HOCHRCH2COO is a stylized structural formula used in organic chemistry to denote a hydroxy-substituted carboxylate with a variable side chain. In this representation, a hydroxyl-bearing carbon is connected to a second carbon bearing a substituent R and a methylene group that leads to a carboxylate group (COO−). The exact identity of R determines the chemical properties, including polarity, sterics, and reactivity, making HOCHRCH2COO applicable to a wide range of hydroxyalkanoates, esters, and related compounds. The corresponding neutral acid form would be HOCHRCH2COOH, while the deprotonated form in salts is HOCHRCH2COO−.

The alpha-like arrangement of the hydroxyl-bearing carbon adjacent to the methylene and carboxylate can give rise to stereochemical complexity: if R and the other substituents on the hydroxy-bearing carbon are different, the center is a stereocenter, allowing enantiomers and diastereomers.

In chemical literature the motif is used as a generic substrate in reaction schemes, catalysis studies, and metabolic pathways where the exact R group is not specified. It is not a single named compound but a family of structures. Related classes include alpha-hydroxy acids and hydroxyalkanoates, which appear as intermediates in synthesis or as monomers for biodegradable polymers. When used in salts or esters, the functional groups are the carboxylate and the hydroxyl-bearing carbon remains the defining feature.