Tetronic acid is a crystalline enolic lactone C4H4O3 that has acidic properties and is the parent compound of acidic compounds obtained by the fermenting action of a mold (Penicillium charlesii) from spoiled corn.
Tetronic acid is used as a precursor of a variety of substituted and ring-fused furans and butenolides. It is an acidic building block for heterocyclic compounds for medicinal applications. It is used for selective O-alkyaltion reactions involving cesium fluoride. It is also used to prepare 3H-furo[3,4-b]quinolin-1-one by reacting with 2-amino-benzaldehyde.
In organic synthesis, it is used as a precursor for other substituted and ring-fused furans and butenolides. It is also forms the structural core of a class of pesticides, known as tetronic acid insecticides, which includes spirodiclofen and spiromesifen.