| The synthesis of an indole salicylate with the required axial chirality for diazonamide A are reported. Atropselectivity in this biaryl system are secured by a proximal sp3 stereogenic center.;A model system for a novel photochemically induced cyclization to of a benzotriazole alkene to give a C(2) disubstituted indolenine is developed. Extension of this model system to an approach toward the synthesis of diazonamide A is described.;The putative reductive activation chemistry of the diazoparaquinone natural products was modeled with Bu3SnH and prekinamycin dimethyl ether along with prekinamycin itself. Reactions in a various combinations of aromatic solvents, with and without the nucleophile benzylmercaptan present, led to isolation of both radical trapping arene adducts and nucleophile capture benzyl thioether products. Based on these product distribution studies, the intermediacy of first, a cyclopentenyl radical, and subsequently, an orthoquinonemethide electrophile, is proposed.;Lastly, the preparation of a Nazarov cyclization precursor and attempted cyclizations aimed at securing the benzo[b]fluorenone core of kinamycin F is detailed. |
