Explain enol form of all these options in diagram and explain how can highest enol content check

Explain enol form of all these options in diagram and explain how can highest enol content check 52. Which of the following compound has enol content ? (c) Ph Ph (d)

Dear Student, 

Correct order is C>B>D>A

Reason: 


As stabalization by resonance is stronger than hyperconjugation. So, the order is as given above.

Moreover to check if enol is stable:
Check the number of alpha hydrogens : more alpha hydrogens, more is hyperconjugation and so more is stability
Check the possibilities of aromatic ring conjugation: more chances of ring conjugation, more is stability
Check the chances of Hydrogen bonding with carbonyl group (chelation): It is to compare monoketone with diketones. Only diketones like given above can show intramolecular hydrogen bonding. All those given above undergo intramolecular hydrogen bonding.


​​​​​​​Regards