Total Synthesis of the C‐1027 Chromophore Core: Extremely Facile Enediyne Formation through SmI₂‐Mediated 1,2‐Elimination

The spontaneous aromatization of the enediyne chromophore of the potent antitumor agent C-1027 generates a p-benzyne biradical, which cleaves double-stranded DNA. The title reaction was developed for the construction of nine-membered-ring enediynes and applied as the final step in the synthesis of the exceptionally unstable core structure of the C-1027 chromophore (see scheme; Boc, MOM, MPM, and TES are protecting groups; Ms=methanesulfonyl).