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.
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?