I. Total synthesis of stemonine. II. Studies towards the total synthesis of kendomycin
Enantioselective total synthesis of (-)-stemonine was achieved via a convergent assembly of acyclic precursors. Key transformations include a Staudinger-aza-Wittig reaction to form the central perhydroazepine ring system and an Iodine-induced tandem cyclization to construct the pyrolidino-butyrolactome framework.
The synthesis of an advanced intermediate leading towards (-)-kendomycin is described. The synthetic scheme features the application of the asymmetric conjugate addition methodology for the early generation of C13-C14 ( E)-trisubstituted olefin, providing an efficient assembly of the ansa chain. Condensation reactions probed the Julia olefination and ortho-directed metallation for attachment of the aromatic system.