Biomimetic Synthesis\nof the Marine-Derived Thioalkaloids\nDassonmycins A and B

A biomimetic synthesis of the marine thioalkaloids dassonmycins\nA and B is reported. The synthesis features a chemoselective reduction\nof a diketopiperazine to form a 2-piperazinone, which undergoes heteroannulation\nwith naphthoquinone to yield dassonmycin A. Dassonmycin A undergoes\nslow cyclization to form dassonmycin B at physiological pH, supporting\na biosynthesis hypothesis that this reaction could occur in the cytosol\nof the bacterial host species.