Ten-Step Total Synthesis of (-)-Andranginine.

The total synthesis of the indole alkaloid (-)-andranginine has been achieved in 10 steps. Key reactions of the synthesis include a nucleophilic addition of acetylenyl anion to chiral N -sulfinyl imine, an intramolecular N -alkylation reaction to close the C ring, and a dienyne metathesis cascade reaction to construct the DE rings. Meanwhile, 16- epi -(-)-andranginine was also obtained with the developed strategy.