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.