HBr + Peroxides: Anti‑Markovnikov Radical Addition (Mechanism + Why)

Learn the radical chain mechanism for anti‑Markovnikov HBr addition with peroxides. Initiation/propagation steps, regioselectivity logic, and practice.

• Reaction: Alkene + HBr + ROOR → Alkyl bromide
• What it does: Adds Br to less substituted carbon (anti‑Mark)
• Typical reagents: HBr + peroxides (ROOR), heat/light
• Key intermediate: Carbon radical
• Driving force: Favorable propagation energetics for HBr; chain reaction
• Exam type: Regiochemistry
• Exam type: Mechanism choice
• Exam type: Predict product