4-Acetoxycyclopent-2-enone: a synthetic equivalent for cyclopentadienone in diels-alder reactions
摘要:
The Lewis acid catalyzed Diels-Alder reactions of 4-acetoxycyclopentenone 5 with both cyclic and acyclic dienes is described. Subsequent base induced elimination of the beta-acetoxy group from the respective cycloadducts leads to bi- and tricyclic enones in good yields. The pi-facial diastereoselectivity of the cycloaddition of 5 with cyclopentadiene is 3:1, in favor of the anti-adduct 6a.