Isolation, Structure Elucidation, and Biomimetic Total Synthesis of Versicolamide B, and the Isolation of Antipodal (−)‐Stephacidin A and (+)‐Notoamide B from <i>Aspergillus versicolor</i> NRRL 35600

Abstract

Stereochemically unique: A new prenylated indole alkaloid, (+)-versicolamide B, has been isolated from cultures of Aspergillus versicolor NRRL 35600. The structure has been assigned by 2D NMR experiments, and confirmed by a biomimetic total synthesis. Versicolamide B is the first member of the paraherquamide/stephacidin family of alkaloids found to possess the anti relative stereochemistry at C19. ent-Stephacidin A and ent-notoamide B were also isolated for the first time.