Synthesis of Atisine, Ajaconine, Denudatine, and Hetidine Diterpenoid Alkaloids by a Bioinspired Approach.

A unified approach to four different (atisine, ajaconine, denudatine, and hetidine) diterpenoid alkaloid skeletons was developed and applied to the total synthesis of the natural products dihydroajaconine ( 2, atisine type) and gymnandine ( 4, denudatine type). The synthesis features a biogenetically inspired strategy that relies on C−H oxidation, aza-pinacol coupling, and aza-Prins cyclization as key steps. [ABSTRACT FROM AUTHOR]