Synthetic studies towards atkamine

Abstract

Atkamine is a complex marine pyrroloiminoquinone alkaloid that comprises a heptacyclic scaffold bearing five different heterocycles and four contiguous stereocenters, and therefore it is a highly challenging target for synthetic chemists. We herein reported a modular synthetic strategy toward this alkaloid, featuring a formal [5 + 2] annulation and an asymmetric Michael addition. The efficient synthesis of the long-chain aliphatic aldehyde and chiral amino acetal fragments have been achieved. A simplified tetracyclic intermediate bearing the core structure of atkamine has been successfully constructed through the formal [5 + 2] annulation.