The number of structural and configurational isomers of a bromo compound, C5H9Br, formed by the addition of HBr to 2-pentyne respectively, are

First possibility is- + 3 2 3 3 2 3 3 2 3 CH –C C–CH –CH +HBr CH –CH=C –CH –CH CH –CH=CBr–CH –CH (1) -> -> 2nd possibility is- + 3 2 3 3 2 3 3 2 3 CH C C CH CH HBr CH C CH CH CH CH CBr CH CH CH (2) -> -> 1 and 2 are structural isomers. From these structural isomers, cis and trans isomers can also be drawn as shown below: Preparation of Alkenes