Studies toward the Total Synthesis of Caribbean Ciguatoxin C-CTX-1: Synthesis of the LMN-Ring Fragment through Reductive Olefin Cross-Coupling

Synthesis of the LMN-ring fragment of Caribbean ciguatoxin C-CTX-1, the principal causative toxin for ciguatera fish poisoning around the Caribbean Sea areas, is described. The key feature of the synthesis is the stereoselective introduction of an angular methyl group on the sterically encumbered seven-membered M-ring by the application of a hydrogen atom transfer-based reductive olefin coupling.