The question asked to react the organic hydroperoxide substrate, $\ce{R-OOH}$, with dilute sulfuric acid, $\ce{H2SO4}$.

In the last step, I removed a proton, making it act like a catalyst, along with the removal of $\ce{H2O2}$. But I am very unsure about its correctness.

Please confirm or correct if this is a wrong answer.

proposed reaction mechanism

  • 6
    $\begingroup$ See, that peroxide was there for a reason. I don't believe it would walk away just like that. $\endgroup$ Jun 14 '16 at 18:32
  • $\begingroup$ I really don't get. Please explain. $\endgroup$ Jun 14 '16 at 19:27
  • $\begingroup$ I would propose something like the Hock rearrangement. It should be especially feasible in this case as double bond participation from the anisole ring is expected. $\endgroup$
    – EJC
    Jun 14 '16 at 21:18

As Marko has commented it is like the Hock rearrangement, which is the migratory step in the cumene process.

It is somewhat similar to the Beckmann rearrangement except that there is an oxygen instead of a nitrogen.


  • The acid protonates the peroxide, generating a great leaving group on electron-deficient oxygen.
  • Migration towards electron-deficient oxygen occurs with loss of water to give an oxonium ion.
  • The migratory aptitude here is determined in the same way as for the Baeyer-Villiger reaction. There is a buildup of positive charge on the migrating carbon during the migratory step, and therefore the group that can best stabilise the charge preferentially migrates. The methoxy-substituted ring is electron-rich and the positive charge is more stabilised on it than on the unsubstituted phenyl group. The methyl group is even worse at stabilising positive charge.
  • Under the dilute acid conditions this oxonium ion is hydrolysed.
  • $\begingroup$ Well done! I should have written it on paper before posting my answer to see the whole process. $\endgroup$
    – Kairat
    Jun 14 '16 at 22:10
  • 3
    $\begingroup$ The magical appearance and disappearance of protons... $$\ce{RR'MeC-OOH ->T[magic] RR'MeC-OOH2+ ->...->T[more magic] RMeCO + R'-OH + H2O}$$ $\endgroup$ Jun 15 '16 at 7:45

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