Total Synthesis of (+)-Superstolide A

A convergent and highly stereocontrolled total synthesis of the cytotoxic macrolide (+)-superstolide A is described. Key features of this synthesis include the use of bimetallic linchpin 36b for uniting the C(1)−C(15) (43) and the C(20)−C(27) (38) fragments of the natural product, a late-stage Suzuki macrocyclization of 49, and a highly diastereoselective transannular Diels−Alder reaction of macrocyclic octaene 4. In contrast, the intramolecular Diels−Alder reaction of pentaenal 5 provided the desired cycloadduct with lower stereoselectivity (6:1:1).