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According to Wikipedia Etard reaction proceed via a ene reaction with chromyl chloride forming a Etard complex(Chromium complex) which is then decomposed by a [2,3] sigmatropic shift to give aldehyde.

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But the reaction given in my textbook is as follows, enter image description here

Mechanism of this reaction suggested by Wikipedia does not create the intermediate of this reaction given in my textbook.The Chromium complex is further hydrolysed to give benzaldehyde.

Some sources which I referred suggest that Etard reaction proceed via a radical mechanism. https://pubs.acs.org/doi/suppl/10.1021/ic200877f/suppl_file/ic200877f_si_001.pdf

What is the correct mechanism of this reaction?Is the Chromium complex given in my textbook correct?

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  • $\begingroup$ Exact copy of- chemistry.stackexchange.com/questions/58381/… $\endgroup$ – Muskaan Feb 1 '20 at 17:53
  • $\begingroup$ Which textbook are you using? $\endgroup$ – Waylander Feb 1 '20 at 17:55
  • $\begingroup$ The answer is within the comments $\endgroup$ – Waylander Feb 1 '20 at 17:56
  • $\begingroup$ Organic chemist can imagine a lot of $wrong$ things with their imaginary arrow pushing constructs. It is not necessary that if the arrows pushing story makes some sense like a typical movie, then it is real story. Only an experiment can draw a reasonable conclusion. Don't be impressed with DFTs or fancy names. Someone jokingly said in a meeting that hardcore theoreticians cannot distinguish between a cow and methane. I am not an organic chemist, but as a student I wasted a lot of time in believing in those arrow pushing mechanisms and thinking that all reaction mechanisms were known. $\endgroup$ – M. Farooq Feb 1 '20 at 18:02
  • $\begingroup$ Look for original papers from the oldest first. A lot of papers appear from 1960s and indeed it is clear that it is a very complex reaction. sciencedirect.com/science/article/abs/pii/S0040402001985722 $\endgroup$ – M. Farooq Feb 1 '20 at 18:02