試題詳解

51. For Diels-Alder cycloaddition reactions to take place most rapidly and in highest yield the dienophile must:
(A) be substituted with electron-withdrawing groups
(B) be able to adopt and s-trans conformation
(C) be substituted with electron-donating groups
(D) be able to adopt an s-cis consformation
(E) none of the above