Question

Which of the following will undergo ring contraction?

• A.
• B.
• C.
• D. None of the above

Answer 1

The correct option is A

Whenever a carbocation is formed in a reaction, it may rearrange. Only those carbocations which can produce more stable forms will rearrange. In option (a), ring contraction will take place because after ring contraction, it will form cyclopropyl methyl carbocation which is more stable than five membered and six membered carbocation. In option (b) and (c), ring expansion will take place and it will form six and five membered ring respectively. Hence, the correct answer will be option (a).