Asymmetric total synthesis of montanine-type amaryllidaceae alkaloids

The first asymmetric total syntheses of (+)-pancratinines B and C and the asymmetric total syntheses of (-)-montanine, (-)-pancracine and (-)-brunsvigine were realized in a divergent fashion. Our synthetic strategy features a copper-catalyzed [3 + 2] annulation reaction, Pictet-Spengler cyclization and an epoxide opening and hydroxyl elimination to form the challenging C100000000000000000000000000000000111111110000000011111111000000000000000000000000C11a bond. The first asymmetric total syntheses of (+)-pancratinines B and C and total syntheses of (-)-montanine, (-)-pancracine and (-)-brunsvigine were realized in a divergent fashion. Our synthetic strategy features a copper-catalyzed [3 + 2] annulation reaction and a Pictet-Spengler cyclization.