Which of the following diene(s) cannot undergo the Diels-Alder reaction?
A) I
B) II
C) III
D) IV
E) I & IV

Question

Which of the following diene(s) cannot undergo the Diels-Alder reaction? 
A) I 
B) II 
C) III 
D) IV 
E) I & IV

Quizplus · Accepted Answer

I cannot undergo the Diels-Alder reaction because it is not a conjugated diene (it has a double bond which is not part of the conjugated system). IV cannot undergo the Diels-Alder reaction because it is an isolated diene, which means that the two double bonds are separated by two or more single bonds (in this case, a methylene group). In order for the Diels-Alder reaction to occur, the diene must be a conjugated diene (which means that the two double bonds are separated by only one single bond). Therefore, the correct answer is choice E, which includes both dienes that cannot undergo the Diels-Alder reaction.

Which of the Following Diene(s) Cannot Undergo the Diels-Alder Reaction