Question

Choose correct order of their stability.

• A. $1>2>3>4$
• B. $3>4>2>1$
• C. $1>2>4>3$
• D. $2>1>4>3$

Answer 1

The correct option is A $1>2>3>4$

(1) and (2) is stabilised through hyperconjugation effect.
(3) and (4) is destabilised by $-I$ effect.
Order of $+H$ effect: $-C{H}_3>C{D}_3$
Order of $-I$ effect: $-OH>OEt$

Hence, the overall stability order becomes$1>2>3>4$