Synthesis of the Tetracyclic Core of Tetrapetalone A Enabled by a Pyrrole Reductive Alkyation

The tetracyclic framework of the tetrapetalone A aglycon has been secured through synthesis. A reductive pyrrole alkylation enables the formation of a key tetrasubstituted carbon stereocenter, and the tetramic acid portion of the molecule can be accessed through silicon or boronic ester conjugate addition to an ene-lactam.