Electrophilic addition to propene without radical reactions

Steps:

• Propene (CH₃CH=CH₂) undergoes electrophilic addition with Br₂ to form the vicinal dibromide, 1,2-dibromopropane.
• Propene reacts with HBr via electrophilic addition, following Markovnikov's rule, to primarily yield 2-bromopropane.
• In the dark, radical mechanisms are absent, limiting anti-Markovnikov addition, but trace 1-bromopropane may form from minor ionic pathways or impurities.
• No mechanism produces 1,1-dibromopropane, as it requires geminal Br addition to the terminal carbon, which does not occur.

Why C is correct:

• Electrophilic addition of Br₂ to alkenes forms vicinal dihalides (Br on adjacent carbons) per the bromonium ion intermediate mechanism, not geminal dihalides like 1,1-dibromopropane (Br₂CHCH₂CH₃).

Why the others are wrong:

• A. 1-bromopropane forms in small quantities via trace non-Markovnikov HBr addition.
• B. 2-bromopropane is the major Markovnikov product from HBr addition.
• D. 1,2-dibromopropane results from standard Br₂ addition across the double bond.

Final answer: C