Question

Anti –markonikoff's addition of HBr is not observed in:

• A. Propene
• B. But -1- ene
• C. 2-butene
• D. 2-pentene

Answer 1

Answer: (C)

2-butene

As 2-butene is symmetrical so it will make same product and there is no use of markovnikoff's rule.
But in case of other options (A, B and D), alkenes are unsymmetrical so it will make a different product when it reacts with HBr in presence of peroxide according to anti-markovnikoff's rule.