Fig. 4. Scheme for the oxidation reactions. (a) The periodate-permanganate oxidation process of carbon–carbon double bonds can be explained in three steps. (b) The reaction of the IO₄^– to regenerate MnO₄^– from its reduced state of MnO₃^–. (c) The disproportionation reaction of MnO₃^– to form the MnO₂ precipitate.