A New Approach to Pyrrolocoumarin Derivatives by Palladium‐Catalyzed Reactions: Expedient Construction of Polycyclic Lamellarin Scaffold

A new and efficient protocol for straightforward synthesis of chromeno[3,4‐ b ]pyrrol‐4(3 H )‐one derivatives by palladium‐catalyzed sequential coupling/cyclization reactions has been developed. The key strategy relies on creation of pyrrole ring through palladium‐catalyzed intramolecular hydroamination of related acetylenic aminocoumarins. The synthetic utility of the obtained chromeno[3,4‐ b ]pyrrol‐4(3 H )‐one product has been demonstrated by the expedient synthesis of polycyclic lamellarin scaffold in four steps. It provides a new entry to synthesis of potentially valuable lamellarin analogues.