Synthetic Study\ntoward Daphnimacropodines

Daphnimacropodines A-C are members of a small but structurally\ndistinct subfamily of <i>Daphniphyllum</i> alkaloids. Their\ncongested polycyclic skeletons, and two vicinal quaternary stereocenters,\npresent significant synthetic challenges. This paper describes two\nstereoselective approaches to constructing the tricyclic core structures\nof daphnimacropodines, achieved through a straightforward Rh-catalyzed\n[4 + 3] cycloaddition using simple building blocks. This work also\nhighlights an intramolecular Heck reaction that rapidly assembles\nthe cyclohexane ring moiety, a Tsuji-Trost allylation that forged\nthe critical C-8 quaternary stereocenter, an efficient hetero-Diels–Alder\nreaction, and an intramolecular nucleophilic addition, which paved\nthe way to the key cyclopentane ring. The assembly\nof the tetrahydropyrrole motif was also investigated.