Manganese dioxide (MnO2) serves as a mild oxidizing reagent for transforming allylic and benzylic alcohols into aldehydes and ketones under neutral conditions. It can be prepared through the reaction of manganese sulfate and potassium permanganate in water. The document outlines the reaction mechanism involving benzyl alcohol converting to benzaldehyde.

1. Manganese dioxide
(MnO2)

2. Manganese dioxide:
 Mild reagent for Oxidation.
 Oxidant for Allylic and Benzylic Alcohol.
 Primary Alcohol yields aldehyde and Secondary Alcohol yields ketone.
 Mild condition in a neutral solvent such as water, petroleum, acetone,
DMF, CH2Cl2, or CHCl3
 Activated MnO2 Preparation:
3MnSO4 + 2KMnO4 + 2H2O → 5MnO2 + K2SO4 + 2H2SO4
manganese
dioxide

3. Reactions:
Benzyl alcohol Benzaldehyde
1.
2.

4. Mechanism:
(dissolves in
the solvent)