객관식
Which of the following statements about the reaction is true?
109
views
16. Conjugated Systems
Diels-Alder Reaction
객관식
Which statement is correct regarding the formation of the - product in a Diels-Alder reaction?
A
The - product forms exclusively when the diene is in the conformation.
B
The - product is typically less thermodynamically stable than the - product due to less favorable secondary orbital interactions.
C
The - product is always the major product under kinetic control.
D
The - product results from the dienophile approaching the diene from the same side as the largest substituent.
검증된 단계별 안내1
Understand the difference between exo and endo products in a Diels-Alder reaction: The endo product results from the dienophile approaching the diene such that substituents on the dienophile are oriented underneath the newly forming ring (towards the diene's π system), while the exo product has these substituents oriented away from the diene's π system.
Recall that the endo product is often favored kinetically due to secondary orbital interactions between the π orbitals of the diene and the substituents on the dienophile, which stabilize the transition state leading to the endo product.
Recognize that the exo product is generally more thermodynamically stable because it experiences less steric hindrance and strain, but it forms more slowly due to the lack of these secondary orbital interactions.
Note that the conformation of the diene (such as s-cis or s-trans) affects whether the Diels-Alder reaction can proceed efficiently, but the exo product does not form exclusively from the s-trans conformation; rather, the s-cis conformation is required for the reaction to occur at all.
Conclude that the correct statement is that the exo product is typically less thermodynamically stable than the endo product due to less favorable secondary orbital interactions, which explains why the endo product is often the major product under kinetic control.
관련 영상
관련 실천
