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Updated: Mar 31, 2026

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Synthesis of Lamellarin D Trimethyl Ether and Lamellarin H via 6π-Electrocyclization
Clemes Dialer1, Dennis Imbri1, Steven Peter Hansen1
1Institute of Organic Chemistry, University of Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany.
Abstract:
An electrocyclic ring closure of a 2-azapentadienyl anion generated in situ from a chalcone and glycine ester is the key step of an efficient synthesis of the pyrrole core of the lamellarin alkaloids. A recently developed scalable one-pot procedure provides multigram quantities of a 3,5-diaryl-4-iodopyrrole-2-carboxylate intermediate which is transformed in four further high-yielding operations including a one-pot Pomeranz-Fritsch alkylation/cyclization and an Ullmann-type lactone ring closure into the pentacyclic lamellarin skeleton.
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