Citraconic acid is an organic compound with the formula CH3C2H(CO2H)2.

The related trans alkene is called mesaconic acid.

[1] Citraconic acid can be produced, albeit inefficiently, by oxidation of xylene and methylbutanols.

The acid displays the unusual property of spontaneously forming the anhydride, which, unlike maleic anhydride, is a liquid at room temperature.

[2] In the laboratory, citraconic acid can be produced by thermal isomerization of itaconic acid anhydride to give citraconic anhydride, which can be hydrolyzed to citraconic acid.