Chapter 14.1, Problem 2P

Interpretation Introduction

Interpretation: The given species is to be identified as conjugated.

Concept Introduction: Diene is a hydrocarbon that contains two $\text{C}=\text{C}$ double bonds in a compound.

Conjugated diene consists of two double bonds that are separated by a single bond, whereas isolated diene also consists of two double bond but they are separated by two more carbon atoms.

The example that shows the basic difference between conjugated diene and isolated diene is shown below.

Figure 1

Allylic carbocation is also an example of conjugated system.