Reaction Mechanism of oxidation of Cyclohexene to Adipic Acid using hot acidic KMnO4

Question

Please help draw or explain the complete reaction mechanism of the oxidation of cyclohexene to adipic acid using hot acidic KMnO_4.

Also how would I find the Literature Value theoretical yield and percentage yield for Adipic Acid so that I can compare them to the experimental values I have?

Answer 1

This reaction will occur in two main steps, that both happen to be done with a single reagent. In the first step, KMnO4 will add across the double bond of cyclohexene to form a ring, much like OsO4, except it is such a strong oxidizing agent that the alkene will be replaced by an aldehyde at each carbon. Two quick arrow pushing steps will take you there.

For the second step, review the oxidation of alcohols/aldehydes - KMnO4 will oxidize those new aldehydes to carboxylic acids. MnO4 is a potent Lewis acid Now I bet this is where you ran into trouble, as a KMnO4 in acid mechanism is not widely available online. But guess what reagent looks almost exactly the same? Chromic acid! KMnO4 oxidation proceeds by basically the same mechanism but replace all instances of Cr with Mn.

Hope this helps!