The first total synthesis of the potent antibiotic anthracimycin was achieved in 20 steps. The synthesis features an intramolecular Diels-Alder reaction to forge the trans-decalin moiety, and an unprecedented aldol reaction using a complex β-ketoester to provide the tricarbonyl motif. A Stork-Zhao olefination and Grubbs ring closing metathesis delivered the E/Z-diene and forged the macrocycle. The C2 configuration was set with a base-mediated epimerization, providing access to (-)-anthracimycin.