Cannizzaro Reaction

                             The cannizzaro reaction is a redox reaction. Two molecules ( aliphatic and aromatic aldehydes ) of an aldehyde are reacted to produce a alcohol and carboxylic acid in the presence of strong base.

   a  -   Keto aldehydes give the product of an intramolecular disproportionation in excellent yields.

Mechanism :

NaOH Na ⁺    +  OH ^–   

 

^{Nucleophilic addition of OH- to aldehyde.}

The Crossed cannizzaro reaction, uses formaldehyde as reducing agent.