Question

The Cannizzaro reaction of formaldehyde involves an:

• A. intermlolecular shift of proton
• B. intermolecular shift of hydride
• C. intramolecular shift of proton
• D. intramolecular shift of hydride

Answer 1

The correct option is B intermolecular shift of hydride

Cannizzaro reaction is a chemical reaction named after Stanislao Cannizzaro that involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to yield a carboxylic acid and a primary alcohol.


Mechanism involves three steps:
1) Nucleophilic attack of hydroxide
2) Hydride transfer
3) Proton transfer

Hydride transfer is the ​rate determining step in Cannizzaro reaction.​
Hence, the correct answer is option (b).