Four‐Component Construction of Coumarin‐Fused Pyrrolo[2,1‐a]isoquinoline: Expedient Synthesis of Lamellarins and Their Regioselective Demethylation

Abstract Construction of the coumarin‐fused pyrrolo[2,1‐ a ]isolquinoline skeleton was realized through a four‐component reaction between isoquinoline, ethyl bromoacetate, o ‐hydroxybenzaldehyde and nitromethane. This methodology was further extended to the synthesis of lamellarin D trimethyl ether and a formal synthesis of lamellarin D. The controlled demethylation of lamellarin D trimethyl ether yielded dihydroxy and tetrahydroxy lamellarin analogues regioselectively.