A High‐Yielding Modular Access to the Lamellarins: Synthesis of Lamellarin G Trimethyl Ether, Lamellarin η and Dihydrolamellarin η

Abstract

A deprotonated α-aminonitrile serves as a key intermediate in a highly efficient (95 % per step on average; see scheme) modular synthetic approach to the lamellarin alkaloids. Its reaction with an α,β-unsaturated aldehyde forms the central pyrrole ring in a one-pot procedure. The construction of the fused pentacyclic skeleton is completed by a microwave-assisted Ullmann-type lactone formation.