Benzylic Oxidation of Cyclic Molecules Using KMnO₄
For the homogenous permanganate oxidation of aromatic side chains, as long as there is at least one benzylic hydrogen, then the side chain will be oxidized to the corresponding benzoic acid.  Here are some examples.



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Look at the third example, the permanganate oxidation of tetralin to phthalic acid.  It is very analogous to your molecule.  Your molecule would also be oxidized to phthalic acid.