Ketanol tautomerism refers to a chemical equilibrium between a keto form (a ketone or an aldehyde) and an enol. The enol and keto fprms are said to be tatutomers of each other. The interconversion of the two forms involved the movements of a proton and the shifting of bonding electrons. A compound containing a carbonyl group $(C=0)$ is normally in rapid equilibrium with an enol tautomer, which contains a pair of doubly bonded carbon atoms adjacent to a hydroxyl $(-OH)$ group, $C=C-OH$ For a carbonyl compound to exhibit tautomerism, the essential condition is that, it must have at least one $ \alpha -H$ atom. Generally , the keto form is more stable than the enol form due to the greater strength of the carbon- oxygen $\pi$ bond as compared - carbon $\pi$ bond. In keto-enol tautomerism of dicarbonyl compounds, the enol form is preferred in contrast to the keto- form , this is due to
