A Synthesis of Lamellarins via Regioselective Assembly of 1,2,3-Differentially Substituted 5,6-Dihydropyrrolo[2,1-a]Isoquinoline Core

Abstract

A modular synthesis of the marine natural products lamellarins has been developed. The key reactions utilized are C3-selective Vilsmeier-Haack formylation followed by iterative bromination/cross-coupling of the 5,6-dihydropyrrolo[2,1-a]isoquinoline core. The 1,2-diaryl-5,6-dihydropyrrolo[2,1-a]isoquinoline-3-carbaldehyde thus synthesized was readily converted to the lamellarin skeleton by mean of palladium-catalyzed oxidative lactonization.