Unified Total Synthesis of Pyrroloazocine Indole Alkaloids Sheds Light on Their Biosynthetic Relationship

The total synthesis of seven members of the lapidilectine and grandilodine family of alkaloids has been accomplished in enantiopure form. The two key steps, an 8-endo-dig hydroarylation and a 6-exo-trig photoredox cyclization, were catalyzed with gold. A rationale for the formation of the cyclopropane ring of the lundurines is also provided.