My Attempt : The correct answer is C. I tried rearranging similar to claisen rearrangement but I have no clue how to go forward. I know that option A is wrong and that the product is pretty easily predictable. But I cannot predict either the product or the mechanism.A detailed solution for each reaction would be very helpful. Thank you.

  • $\begingroup$ fyi (D) gives pyrazole. It is known as the Pechmann pyrazole synthesis drugfuture.com/OrganicNameReactions/onr296.htm $\endgroup$ – Waylander Jun 10 '20 at 8:37
  • $\begingroup$ It's hard for me to imagine that (C) does not take place at some level. $\endgroup$ – Zhe Jun 10 '20 at 14:38
  • $\begingroup$ Can you imagine that C takes part to form something? $\endgroup$ – Anand Maneesh Jun 10 '20 at 16:23
  • $\begingroup$ Unlikely that B is the correct answer because of the oxidation state. Loss of acetic acid gives a nitrile but there is no way to add acetate to the ring. The oxime of benzaldehyde is dehydrated with Ac2O to benzonitile and acetic acid, i. e., the intermediate is B's starting material. C, as @Zhe has suggested, is the likely answer. $\endgroup$ – user55119 Jun 10 '20 at 23:26
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    $\begingroup$ I think we have helped you enough. As to a mechanism for C, I suggest you Google thermolysis (pyrolysis) of esters. $\endgroup$ – user55119 Jun 11 '20 at 2:13