Studies directed towards total synthesis of saframycin: I. A synthesis of hexahydro-1,5-imino-3-benzazocin-7,10-dione.

A short-step synthesis of 2, the right-hand half of antibiotic saframycin (1), is described. The key steps of this synthesis are the acid catalyzed intramolecular double cyclization of 4 and the oxidative demethylation of 7 to the quinone (2).