A simple biomimetic synthesis of styelsamine B.

An extremely rapid, low cost, and environmentally friendly entry into the pyridoacridine family of alkaloids has been devised, as demonstrated here by the first total synthesis of styelsamine B (3) and its oxidation to the quinoneimine cystodytin J (4). The known reaction of cystodytin J with methanethiol makes this a formal synthesis of diplamine. [reaction: see text]