Which of the following dienes contain conjugated double bonds?

Question

Quizplus · Accepted Answer

A conjugated diene is one where there are alternating double and single bonds with no intervening sp3 hybridized carbon atoms. In compound I, there are two double bonds separated by a single bond, making the diene conjugated. In compound II, there are two double bonds, but they are not conjugated as they are separated by two singly bonded carbons. In compound III, there are three double bonds, two of which are conjugated. In compound IV, there are two double bonds separated by a sp3 hybridized carbon atom, making the diene non-conjugated. Therefore, the only compounds that contain conjugated double bonds are I and III.

Which of the Following Dienes Contain Conjugated Double Bonds