Chemistry - STRUCTURAL ISOMERISM Question with Solution | TestHub

In but-1-ene, CH₂=CH-CH₂-CH₃, D can replace H at four structurally distinct positions : C-1, C-2, C-3 and C-4 $\to$ 4 isomers. In buta-1,3-diene, CH₂=CH-CH=CH₂, there are only two distinct positions : C-1 (terminal) and C-2 (internal) $\to$ 2 isomers. Hence 4 and 2.