Arrange the following compounds in the strictly decreasing order of their percentage enol content at — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

The enol form of phenol (III) is overwhelmingly dominant (~100%) because it generates a highly stable $6\pi$ aromatic ring. Acetylacetone (II) is a $\beta$ -diketone, whose enol content is exceptionally high (~76%) due to internal hydrogen bonding forming a stable chelate ring and extended conjugation. Acetone (I) is a simple mono-ketone where the keto form is vastly more stable due to the high $C=O$ bond energy, resulting in negligible enol content. Thus, III > II > I.