2-Hydroxyisobutyric acid

2-Hydroxyisobutyric acid is the organic compound with the formula (CH3)2C(OH)CO2H. A white solid, it is classified as an hydroxycarboxylic acid. It has been considered as a naturally occurring precursor to polyesters. It is closely related to lactic acid (CH3CH(OH)CO2H).

Occurrences
The enzyme 2-hydroxyisobutyryl coenzyme A (CoA) mutase isomerizes 3-hydroxybutyryl coenzyme A into 2-hydroxyisobutyryl coenzyme A. Hydrolysis of the latter gives 2-hydroxyisobutyric acid.

The amides formed from this carboxylic acid and the ε-amino group of lysine residues are a kind of post translational modification.

Ethyl methacrylate (an industrially important monomer and ester of methacrylic acid) was first obtained by treating the ethyl ester of 2-hydroxyisobutyric acid with phosphorus pentachloride in an apparent dehydration reaction.