A reductone is a special class of organic compounds. They are enediols with a carbonyl group adjacent to the enediol group, i.e. RC(OH)=C(OH)-C(O)R. The enediol structure is stabilized by the resonance resulting from the tautomerism with the adjacent carbonyl. Therefore, the chemical equilibrium produces mainly the enediol form rather than the keto form.[1]
Reductones are reducing agents, thus efficacious antioxidants. Some are fairly strong acids.[2]
Examples of reductones are tartronaldehyde, reductic acid and ascorbic acid.