Intramolecular Rhodium-Catalyzed [(3+2+2)] Carbocyclization Reactions with Dienylidenecyclopropanes: A Concise and Stereoselective Total Synthesis of the Sesquiterpene (+)-Zizaene
Zhu Yu, Jie Zheng, P. Andrew Evans
Abstract
The development of an intramolecular rhodium-catalyzed [(3+2+2)] carbocyclization reaction of alkylidenecyclopropanes (ACPs) tethered to 1,4- and 1,5-skipped dienes is described. This transformation offers a new approach for the construction of bridged tricyclic compounds with up to three quaternary centers, which are suitable for the synthesis of challenging bioactive natural products. For instance, the synthetic utility of this transformation is illustrated through a concise asymmetric total synthesis of the sesquiterpene (+)-zizaene in ten steps from a commercially available starting material.
Topics & Concepts
ChemistrySesquiterpeneIntramolecular forceRhodiumTotal synthesisStereoselectivityStereochemistryCyclopropanationCatalysisCope rearrangementIntramolecular reactionCombinatorial chemistryOrganic chemistryCyclopropane Reaction MechanismsCatalytic Alkyne ReactionsSynthetic Organic Chemistry Methods