Question

The mechanism involved in formation of haloarenes by Hunsdiecker reaction proceed via formation of:

• A. alkyl hypohalite
• B. aryl hypohalite
• C. acyl hypohalite
• D. none of these

Answer 1

Answer: (C)

acyl hypohalite

Hunsdiecker reaction is a halogenation reaction. The reaction mechanism of the Hunsdiecker reaction is believed to involve organic radical intermediates. The silver salt of the carboxylic acid 1 will quickly react with bromine to form acyl hypohalite intermediate 2. Formation of the diradical pair 3 allows for radical decarboxylation to form the diradical pair 4, which will quickly recombine to form the desired organic halide 5.