Biomimetically inspired short access to the 2-aminoimidazole-fused tetracyclic core of (+/-)-dibromoagelaspongin.

A six-step synthesis of the tetracyclic core of the natural compound (+/-)-dibromoagelaspongin, isolated from Agelas sp. Sponge, was achieved from the commercially available 5-aminopentan-1-ol, 2-trichloroacetylpyrrole, and 2-aminopyrimidine. Following a biomimetic inspired approach, successive oxidative reactions including the final DMDO biomimetic oxidation gave the interesting triaminomethane-fused core.