Which of the compounds has the highest percentage of enol?

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

Coming to your question:

3,4 - there's no α-hydrogen (no enolisable hydrogen).So, no tautomerisation takes place

1- has 99% keto content

2- is expected to have more enol content due to extended conjugation of the π-electrons of the double bond formed after enolisation with the phenyl rings.

ANS: 2 has the highest enol content.

Related videos on Youtube

47 : 09

Isomerism 05 || Tautomerism 02 || Percentage of Enol Content N Stability of Enol JEE MAINS / NEET ||

Physics Wallah - Alakh Pandey

842

11 : 15

Keto Enol Tautomerism - Acidic & Basic Conditions

The Organic Chemistry Tutor

151

08 : 07

Keto Enol Tautomerism And How To Determine Which Molecule Has An Enol Form? A Super Easy Way!

Mayya Alocci

22

05 : 12

Trick to Find Enol Content |JEE main and advanced| NEET| KVPY

NEET kaka JEE

15

04 : 32

Enol content is maximum in

Doubtnut

7

Author by

Tapi

Updated on January 30, 2023