Asymmetric [4 + 3] cycloadditions between vinylcarbenoids and dienes: application to the total synthesis of the natural product (-)-5-epi-vibsanin E.

ABSTRACT: The total synthesis of (-)-5-epi-vibsanin E (2) has been achieved in 18 steps. The synthesis combines the rhodium-catalyzed [4 + 3] cycloaddition between a vinylcarbenoid and a diene to rapidly generate the tricyclic core with an effective end game strategy to introduce the remaining side-chains. The [4 + 3] cycloaddition occurs by a cyclopropanation to form a divinylcyclopropane followed by a Cope rearrangement to form a cycloheptadiene. The quaternary stereogenic center generated in the process can be obtained with high asymmetric induction when the reaction is catalyzed by the chiral dirhodium complex, Rh(2)(S-PTAD)(4).

SUBMITTER: Schwartz BD 

PROVIDER: S-EPMC2717789 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature