10.1002/anie.202101439
Gustav J. W?rmer, Nikolaj L. Villadsen, Peter N?rby, and Thomas B. Poulsen, present a highly concise and asymmetric synthesis of the alkaloids Streptazone A and Abikoviromycin, which feature an unusual arrangement of reactive functionalities within a compact tricyclic ring system. The synthesis involves constructing Streptazone B1 using a rhodium-catalyzed distal selective allene-ynamide Pauson-Khand reaction, followed by a regio- and enantioselective epoxidation under chiral phase-transfer catalytic conditions to obtain Streptazone A in just 8 steps. Abikoviromycin is then synthesized in one additional step through a chemoselective, iridium-catalyzed reduction of the enaminone system. The study also investigates the reactivity of Streptazone A towards a cysteine mimic, N-acetylcysteamine, revealing unanticipated transformations, including bis-thiol conjugation that may proceed via the formation of a cyclopentadienone intermediate.