Which two organic chemists are known for observing the peroxide effect in adding reagents to unsaturated compounds in 1933?

Correct option is A

The correct answer is (a) Morris S. Kharasch and Frank R. Mayo.
· In 1933, Morris S. Kharasch and Frank R. Mayo observed the peroxide effect, also known as the Kharasch effect, in the addition of reagents like hydrogen bromide (HBr) to unsaturated compounds (e.g., alkenes). This effect is characterized by the reversal of Markovnikov's rule in the presence of organic peroxides, leading to anti-Markovnikov addition.
Key Details:
· Peroxide Effect: When hydrogen bromide (HBr) is added to alkenes in the presence of organic peroxides, the bromine attaches to the less substituted carbon atom (anti-Markovnikov addition).
· Mechanism: The reaction proceeds via a free-radical chain mechanism, initiated by the decomposition of peroxides to form free radicals.
· Significance: This discovery expanded the understanding of reaction mechanisms and free-radical chemistry.