Strychnine is a terpene indole alkaloid belonging to the Strychnos family of Corynanthe alkaloids, and it is derived from tryptamine and secologanin [REF].
A reverse Pictet-Spengler reaction cleaves the C2-C3 bond, while a subsequent Mannich reaction forms the C3-C7 bond, and a Michael addition forms the C2-C16 bond to provide dehydropreakuammicine.