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 racemic and enantiopure
form without protection/deprotection of functional groups. The two
key steps, an 8-endo-dig hydroarylation and a 6-exo-trig photoredox cyclization, were catalyzed using gold.
A rationale for the formation of the cyclopropane ring of the lundurines
is also provided.