Chain oxidation with permanganate and dichromate

Hot potassium permanganate and dichromate oxidize alkylbenzenes to benzoic acids. This reaction is only possible if there is at least one hydrogen in the benzylic position. The length of the chains does not matter, or if they are branched, they all break through the benzylic position, generating the carboxylic group.
oxidation side chains 01
Without hydrogens in the benzylic position, cleavage does not occur.
oxidation side chains 02