Question

Explain with an example of the following reaction:

Hunsdiecker reaction

Answer 1

The Hunsdiecker reaction is a decarboxylation reaction in which a silver salt of a carboxylic acid reacts with a halogen (Br₂ or Cl₂) to form an alkyl halide, along with CO₂ and a silver halide.

\[\ce{\underset{Silver butanoate}{CH3CH2COOAg} + Br2 →[CCl4][Heat]\underset{Bromopropane}{CH3CH2Br} + CO2 + AgBr}\]

Here, silver butanoate reacts with bromine to give bromopropane, carbon dioxide, and silver bromide. This reaction removes the carboxyl group as CO₂ and replaces it with a halogen, useful for preparing alkyl halides by decarboxylation.