Question

is heated with conc. $H_{2}S{O}_4$. The cycloalkene formed is

• A.
• B.
• C.
• D. a

Answer 1

The correct option is D a

Alcohols on heating with con.$H_{2}S{O}_4$ undergoes dehydration. Initially the $OH$ gets protonated to form a primary carbocation which undergoes ring expansion to form a stable five member ring. Finally the proton abstraction takes place to form a alkene product.


Expansion of cyclobutyl ring to cyclopentane ring decreases the diviation of the angle and, threby, angle strain and increase the stability.

Hence, option (d) is correct.