Synthetic progress toward the marine natural product zamamiphidin A.

An asymmetric synthetic approach to the octahydrofuro[3,4- b ]pyridine framework of marine natural product zamamiphidin A has been described. The key steps include an asymmetric Michael addition of ( R )- N-tert -butanesulfinyl imidate with enamidomalonate to install the C10 stereocenter, an intramolecular alkoxide exchange/Michael addition/hydrogenation sequence to construct the bicyclic ring system.