Potassium permanganate (KMnO4) is a very strong oxidant able to react with many functional groups, such as secondary alcohols, 1,2-diols, aldehydes, alkenes, oximes, sulfides and thiols. KMnO4 will readily react with a carbon-carbon double bond before oxidizing a primary alcohol.
Potassium permanganate is soluble in acetone, water, pyridine, methanol and acetic acid. It is also readily soluble in inorganic solvents.
A potassium permanganate (KMnO4) solution is a test for unsaturation (alkenes and alkynes) or functional groups that can be oxidized (aldehydes and some alcohols, Figure 6.66). The permanganate ion (MnO−4) is a deep purple color, and upon reduction converts to a brown precipitate (MnO2).