l Synthesis of (±)-Axinellamines A and B

摘要

The axinellamines (1, 2, Figure 1), isolated by Quinn and co-workers in 1999, are among the most complex marine natural products isolated to date.[1] The intricate architecture of these molecules includes a tetracyclic bisguanidine core with eight contiguous stereocenters. The highly polar nature of the two guanidine units present in 1 and 2 further complicate the practical aspects of dealing with such molecules. Indeed, together with the massadines and palau'amines (see Figure 1 in the preceeding communication for structures),[2] these molecules represent a complexity frontier for chemical synthesis. Despite extensive efforts by many groups, a solution to this puzzle has thus far remained elusive.[3], [4] Herein, we present the first total synthesis of axinellamines A (1) and B (2).