title: A convergent synthesis of the cardenolide skeleton: intramolecular aldol condensation via reduction of alpha-bromoketones.
abstract: Synthesis of the highly biologically valuable cardenolide backbone was achieved via anionic polycyclization. Bromoketone 18, obtained from double-Michael cycloaddition between cyclohexenone 14 and gamma,delta-unsaturated beta-ketoester 16, was efficiently aldolized under reductive conditions. The highly functionalized tetracyclic compound 52 is an important synthetic intermediate that is potentially amenable to natural cardenolide total synthesis.
authors.affiliation: Laboratoire de synthèse organique, Département de chimie, Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 13e Avenue nord, Sherbrooke, Québec J1H 5N4, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Chapdelaine
authors.forename: Julie
authors.initials: J
authors.lastname: Belzile
authors.forename: Pierre
authors.initials: P
authors.lastname: Deslongchamps
mesh_terms: D002298:Cardenolides / Q000138:chemical synthesis*; D007659:Ketones / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D013256:Steroids / Q000138:chemical synthesis; D013329:Structure-Activity Relationship
chemical_list: D002298:Cardenolides; D007659:Ketones; D013256:Steroids