Croconic acid
![Skeletal formula](/Images/godic/202501/07/Croconic_acid.svg2220.png")
![Ball-and-stick model](/Images/godic/202501/07/Croconic-acid-3D-balls2220.png")
![Space-filling model](/Images/godic/202501/07/Croconic-acid-3D-spacefill2220.png")
Croconic acid or 4,5-dihydroxycyclopentenetrione is a chemical compound with formula C5H2O5 or (C=O)3(COH)2. It has a cyclopentene backbone with two hydroxyl groups adjacent to the double bond and three ketone groups on the remaining carbon atoms. It is sensitive to light, soluble in water and ethanol and forms yellow crystals that decompose at 212 °C.