Question

The number of structural and configurational isomers of a bromo compound, $C_5{H}_{9}Br$, formed by the addition of HBr to 2-pentyne is _______ respectively.

• A. 1 and 2
• B. 2 and 4
• C. 4 and 2
• D. 2 and 1

Answer 1

The correct option is B 2 and 4

The number of structural and configurational isomers of a bromo compound, $C_5{H}_{9}Br$, formed by the addition of $HBr$ to 2-pentyne respectively, is 2 and 4.

I and III are structural isomers; I and II, III and IV are diastereomers (or four configurational isomers).