Doubt from stabilities

In question 1 i got order as 5>3>2>4>1 but in answer key mentions 5>4>3>2>1 why

In 2 and 3. There are methyl groups on both the double bonded carbons. Due to the +I nature of methyl group. It destabilises the negative charge caused due to hyperconjugation on the other carbon. Like:

Also.. another explanation could be equivalent resonance structures in the case of 4 which causes more stability.

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Question no 4 and 5

Is 4. d?

No answer key says option A

I guess I was considering hyperconjugative structures.

If you take each carbocation separately, in (A) the +ve charge will undergo resonance and a positive charge will be induced in the tertiary carbon. In (D) +ve charge is induced in a secondary carbon and hence less stable.

Is it d for 5th one?


  1. In D, there is +I effect from methyl group. Also.. the two double bonds in the ring stabilize the positive charge by undergoing conjugation.
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It should be option A

For 5th it should be D because of more conjugation than any other molecule