Synthesis of a Ring-Expanded Bryostatin Analogue

A ring-expanded bryostatin analogue was synthesized by utilizing a Ru-catalyzed tandem tetrahydropyran formation, a Pd-catalyzed tandem dihydropyran formation, and a ring-closing metathesis (RCM) as key steps. The analogue possesses potent antitumor activity against the NCI-ADR cancer cell line with an IC50 of 123 nM.