The Thermodynamics of Enol Formation

Based on bond dissociation energies (DDEs, Table 2.2), the keto form will dominate keto-enol equilibria for common carbonyl-containing structures. However, in many cases, enols can be spectroscopically observed or isolated, and in some cases they even dominate the equilibrium. 

Equilibrium Constants for Keto-Enol Tautomerization Reactions (K = enol]/[keto])  

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