title: Synthesis of Lamellarin D Trimethyl Ether and Lamellarin H via 6π-Electrocyclization.
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.
authors.affiliation: Institute of Organic Chemistry, University of Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany.
authors.forename: Clemes
authors.initials: C
authors.lastname: Dialer
authors.affiliation: Institute of Organic Chemistry, University of Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Imbri
authors.affiliation: Institute of Organic Chemistry, University of Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany.
authors.forename: Steven Peter
authors.initials: SP
authors.lastname: Hansen
authors.affiliation: Institute of Organic Chemistry, University of Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Opatz
mesh_terms: D000478:Alkylation; D000838:Anions / Q000737:chemistry*; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D004987:Ethers / Q000737:chemistry*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D007546:Isoquinolines / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000838:Anions; D003374:Coumarins; D004987:Ethers; D006576:Heterocyclic Compounds, 4 or More Rings; D007546:Isoquinolines; D011758:Pyrroles; C455554:lamellarin D; C455555:lamellarin H