Enantioselective Total Synthesis of the Cyclotryptamine Alkaloid Idiospermuline

Abstract

Stereogenic quaternary carbons present the primary challenge in the syntheses of trispyrrolidinoindoline alkaloids such as idiospermuline. In its synthesis the two contiguous quaternary centers are expediently addressed by combining the lithium dienolate of a differentially protected dihydroisoindigo with a tartrate-derived electrophile. The third quaternary stereocenter is introduced by a catalytic asymmetric Heck reaction.