Convergent and Scalable\nSecond-Generation Synthesis\nof the Fully Functionalized HIJKLMN-Ring Segment of Caribbean Ciguatoxin\nC‑CTX‑1

A highly convergent and scalable\nsecond-generation synthesis\nof\nthe fully functionalized HIJKLMN-ring segment of Caribbean ciguatoxin\nC-CTX-1, the primary toxin responsible for ciguatera fish poisoning\nin the Caribbean Sea and the Northeast Atlantic regions, has been\naccomplished. Key aspects of the synthetic approach include the efficient\nsyntheses of the HI- and KLM-ring fragments on gram scales, a convergent\nfragment coupling toward the HIJKLM-ring skeleton based on the Suzuki–Miyaura\ncoupling strategy, and optimized iron hydride-catalyzed hydrogen atom\ntransfer-mediated olefin coupling conditions for constructing the\nN-ring.