Question

Elimination reaction of $2-Bromo-pentane$ to form $pent-2-ene$ is :
(a) $\beta$-Elimination reaction
(b) Follows Zaitsev rule
(c) Dehydrohalogenation reaction
(d) Dehydrationreaction

• A. (a), (b), (c)
• B. (a), (c), (d)
• C. (b), (c), (d)
• D. (a), (b), (d)

Answer 1

Answer: (A)

This reaction is an example of $\beta$-elimination.Hydrogen is removed from $\beta -$ carbon and halogen from $\alpha$-carbon, hence dehydrohalogenation reaction. Pent-2-ene is major product known as Saytzeff's product and it is more stable alkene than Pent-1-ene.
Generally, in $E_2$ reaction Zaitsev alkene is formed as a major product (more stable alkene).