Question

Which of the following carbocations can undergo a rearrangement to form relatively more stable carbocation?

• A.
• B.
• C.
• D.

Answer 1

Answer: (A), (B), (C)

The correct options are
A
B
C


In (a), primary carbocation is less stable so they will undergo 1, 2- hydride shift to form a stable tertiary carbocation.


In (b), the secondary carbocation will undergo 1, 2- methyl shift to give more stable tertiary carbocation.

In (c), again unstable primary carbocation undergoes 1, 2 -Hydride shift to give stable tertiary carbocation.


In (d), the benzyl ion is already stabilised by resonance of benzene ring so it does not undergo any rearrangement.


Hence, option (a), (b) and (c) are correct.