Asymmetric Total Synthesis of Lepadiformine C Using Memory of Chirality in an Intramolecular Ester Enolate Michael Addition.

The asymmetric synthesis of lepadiformine C was achieved using d-proline as the only chiral source. The synthetic strategy features the use of the principle of "memory of chirality" in an intramolecular Michael addition to construct the bicyclic intermediate without the aid of external chiral sources. A brief mechanistic rationale is presented to account for the stereochemical outcome.