Here the alkene goes through a transfer of electrons as well as atoms, an example
of oxidation. Oxidation is always accompanied by reduction. Here,
KMnO4 loses bonds to oxygen and becomes MnO2. It is reduced.
The alkene gains two bonds to oxygen becoming oxidized.
Since there are electrons being transferred, we cannot draw reaction paths very easily. There is still a useful
picture that explains the chemistry of this reaction quite well. Since permanganate, MnO4-, is the
active reagent, we can imagine that there is some interaction between the pi bond of the alkene and the oxygens on the
Mn. If we imagine that the transfer of atoms is synchronous, that is happens at the same time, then the O atoms that become
alcohols would be on the same side of a ring and be cis. Thus, the product is a cis diol, the observed product.
