# Which of the compounds has the highest percentage of enol? [closed]

Which of the compounds has the highest percentage of enol?

1. $$\ce{CH3-CHO}$$

2. $$\ce{Ph2-CH-CHO}$$

3. $$\ce{Ph-CO-Ph}$$

4. Parabenzoquinone

How do I compare these?

How do I compare these?

You could expect higher enol content in the following cases:

1.If there is an active methylene group ( or any other acidic $$\ce{C-H}$$ bond )

2.Extended conjugation in the enol form

3.Attainment of aromaticity after enolisation

4.Any intramolecular hydrogen bonding possibility in the enol form