title: Studies on the total synthesis of lactonamycin: synthesis of the CDEF ring system.
abstract: A concise and efficient synthesis of the tetracyclic CDEF ring system of lactonamycin (1) is described. The key step involved the Lewis acid mediated, intramolecular Friedel-Crafts acylation of carboxylic acid 6 to produce the tetracyclic CDEF core structure of target 1. The synthesis of 6 was carried out using a high-yielding Negishi coupling of benzyl bromide 7 with triflate 8, which was accessible in 11 steps and 31% overall yield on a multigram scale starting from trihydroxy acid 9.
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, England.
authors.forename: Hermut
authors.initials: H
authors.lastname: Wehlan
authors.forename: Eva
authors.initials: E
authors.lastname: Jezek
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lebrasseur
authors.forename: Grégoire
authors.initials: G
authors.lastname: Pavé
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Roulland
authors.forename: Andrew J P
authors.initials: AJ
authors.lastname: White
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Burrows
authors.forename: Anthony G M
authors.initials: AG
authors.lastname: Barrett
mesh_terms: D007211:Indoles / Q000138:chemical synthesis; D009285:Naphthoquinones / Q000138:chemical synthesis
chemical_list: D007211:Indoles; D009285:Naphthoquinones; C102442:lactonamycin