We have achieved the divergent total synthesis of four kopsane alkaloids which share a complex heptacyclic caged ring system. Key transformations include an asymmetric Diels–Alder reaction to assemble the central bicyclo[2.2.2]octane moiety and the quaternary stereocenter at C20, a SmI2‐mediated cascade reduction/aldol reaction to construct the five‐membered ring and the quaternary stereocenter at C7, and a late‐stage cascade reductive amination/cyclization to establish the highly strained caged ring system.
We have achieved the divergent total synthesis of four kopsane alkaloids which share a complex heptacyclic caged ring system. Key transformations include an asymmetric Diels-Alder reaction to assemble the central bicyclo[2.2.2]octane moiety and the quaternary stereocenter at C20, a SmI 2 -mediated cascade reduction/aldol reaction to construct the five-membered ring and the quaternary stereocenter at C7, and a latestage cascade reductive amination/cyclization to establish the highly strained caged ring system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.