Chem 52 (W03): Demonstration of Alcohol Oxidation

Three different types of alcohols (1º, 2º, 3º) are oxidized with basic potassium permanganate (MnO₄^-/HO^-). The amount of MnO₂ formed gives a colorimetric indication of the extent to which each alcohol is oxidized.

Compare the mechanisms and results from this permanganate oxidation with the chromium oxide and PCC oxidation chemistry described in McMurry (section 17.8).

What other types of oxidation occur with permanganate?

Primary Alcohols

vi

vii

Proton

transfer

vii

Secondary Alcohols

Tertiary Alcohols

Color Change:

MnO₄^- (purple) → HMnO₄^-

3HMnO₄^- + H₂O → 2MnO₂ (brown) + MnO₄^- + 5HO^-