Reaction of alkenes with KMnO4 in aqueous base

Reactions of Alkenes:
Electrophilic Additions
HBr
Br2
H2O/H+ >
KMnO4 H2O
H2 / Pt (metal)
The Formation of a Glycol (diol)
 

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.