Total synthesis of crisamicin A

Stereoselective total synthesis of natural product crisamicin A (1) was accomplished for the first time via the Pd/TMTU-catalyzed alkoxycarbonylative annulation to generate a unique cis-pyran-fused lactone, an intermolecular Diels-Alder reaction to construct the pyranonaphthoquinone unit, and a novel Pd-thiourea pincer complex-catalyzed homocoupling of functionalized naphthoquinones.