The first asymmetric totalsynthesis of (−)‐stemonamine is described. The key reactions included intramolecular acylation to construct the seven‐membered ring and a tandem [2+2] cycloaddition‐Dieckmann condensation reaction using an ynolate to form the fullysubstituted cyclopentenone moiety. Racemization and epimerization of the naturalproduct were first experimentally demonstrated.