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In the image, what would happen after step 2?

  1. Will a double bond be formed between carbon 3 and 4? If this is the case, then we would get benzene in the end.
  2. But, if the positive charge in shifted to carbon 1, then won't it be a more stable carbocation?
  3. Also, if a double bond were to be formed between carbon 1 and 4 now, it would be more substituted than a double bond between carbon 3 and 4.

In spite of all these factors, the double bond is formed between carbons 3 and 4, and benzene is formed.

Kindly explain how this process takes place.And, please tell me how to name this compound.

  • $\begingroup$ I'm suspicious of making a primary carbocation. It's possible that you would get a concerted shift, but even next to a cyclopropane, that looks bad... $\endgroup$
    – Zhe
    Commented Oct 19, 2016 at 15:06

1 Answer 1


The following takes place- not available

And then H3O+ can be assumed to give H+ and H2O. Try it out and you'll get to the product.

If the positive charge is shifted to carbon 1, it would form a more stable alkene since it is more substituted. But after formation of C1-C4 double bond, no further reaction will occur since after expansion + charge will be on a double bonded carbon which would be highly unstable. Since Benzene is more stable than the product which will be formed after shifting of + charge to Carbon 1, and since heat is also applied, there will be enough energy to form more stable benzene and thus the reaction takes place in such a manner.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ Commented Oct 25, 2015 at 12:44

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