Question

Find the total cyclic structural isomers of $C_4{H}_6$

• A. 2
• B. 3
• C. 4
• D. 5

Answer 1

The correct option is D 5

For a compound with molecular formula $C_c{H}_h{X}_x{N}_n{O}_o$

$\text{Degree of unsaturation}=(c+1)-\frac{h}{2}-\frac{x}{2}+\frac{n}{2}$

Molecular formula of the given compound is $C_4{H}_6$
$\text{Degree of unsaturation}=(4+1)-\frac{6}{2}=2$

Since, it is a cyclic isomer. It must contain one ring structure and one double bond. Thus, the cyclic structural isomers are 5.