Question

(∩ ͡° ͜ʖ ͡°)⊃━✿✿✿✿✿✿

⚽Question for chemistry experts⚽

Explain ur answer...

Answer 1

• Tautomerization takes place in such compounds who has keto group or enol group. i.e. they can interchange in to each other to form more stable compound.

1. In 1st option there is bridge head keto group. Its enol is not stable due to formation of πbond at bridge head carbon. So, no tautomerization.
2. In 2nd option, on forming enol compound, there are two possibilities.1st is that pibond can be formed through bridge head carbon and 2nd is that pibond is from through carbon attached with 2 phenyl groups. but in 1st case unstable sructure. hence rejected. in 2nd case no αH to form pibond. hence, No tautomerization.
3. similarly in 3rd option no αH from both the sides to form enol compound. hence no tautomerization.

    4. but in 4th option, from right hand side there is methyl group attached to the pibonded carbon atom. Hence its resonating structure can be formed . due to which enol compound can be formed.

for better understanding see the below attachment