Enantioselective Total Synthesis of (−)‐Lansai B and (+)‐Nocardioazines A and B

Abstract

The concise total syntheses of the bis(pyrroloindolines) (-)-lansai B and (+)-nocardioazines A and B are reported. The key pyrroloindoline building blocks are rapidly prepared by enantioselective formal [3+2] cycloaddition reactions. The macrocycle of (+)-nocardioazine A is constructed by an unusual intramolecular diketopiperazine formation.