Baeyer's Test

 

Baeyer’s reagent is an alkaline solution of cold potassium permanganate (KMnO4). It is a useful oxidizing agent and is used in qualitative organic analysis to test for the presence of unsaturation. This solution interacts with an unsaturated compound (e.g., alkene and alkyne), changing its pinkish-purple color to brown. The alkene is oxidized to 1,2-diol, while the permanganate is reduced to MnO2. This is an important reaction because it does not work on alkanes or aromatic compounds, and hence, can be used to distinguish them from alkenes and alkynes.