title: A photoinduced cyclization cascade-total synthesis of (-)-leuconoxine.
abstract: A protecting-group-free and enantioselective total synthesis of the monoterpenoid indole alkaloid (-)-leuconoxine was accomplished. The key step comprises a novel photoinduced domino macrocyclization/transannular cyclization involving the Witkop cyclization, for which additional mechanistic evidence is provided. This process furnishes a diaza[5.5.6.6]fenestrane skeleton, which is a hitherto unprecedented structure element.
authors.affiliation: Institute of Organic Chemistry, Leibniz University of Hannover, Schneiderberg 1b, 30167 Hannover (Germany).
authors.forename: Magnus
authors.initials: M
authors.lastname: Pfaffenbach
authors.forename: Tanja
authors.initials: T
authors.lastname: Gaich
mesh_terms: D003500:Cyclization; D026121:Indole Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D055668:Photochemical Processes; D046948:Secologanin Tryptamine Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D026121:Indole Alkaloids; D046948:Secologanin Tryptamine Alkaloids; C000590191:leuconoxine
keywords: fenestrane; indole alkaloid; total synthesis; transannular cylization; witkop photocyclization