Progress Toward the Total Synthesis of Hamigerans C and D: A Direct Approach to an Elaborated 6-7-5 Carbocyclic Core

The hamigeran family of natural products has been the target of numerous synthetic efforts due to its biological activity and interesting structural properties. Herein we disclose our efforts toward the synthesis of hamigerans C and D, unique among the initially isolated members due to their 6-7-5 carbocyclic core. Our approach directly targets this tricyclic motif by sequential Negishi and Heck coupling reactions, yielding an advanced intermediate with all necessary carbons and sufficient functionality poised for completion of the synthesis of these two natural products.