title: Total synthesis of 7- and 8-oxygenated pyrano[3,2-a]carbazole and pyrano[2,3-a]carbazole alkaloids via boronic acid-catalyzed annulation of the pyran ring.
abstract: The boronic acid-catalyzed annulation of citral opens up a short route to oxygenated cyclized monoterpenoid pyranocarbazole alkaloids. Thus, murrayamine-D is available in only three steps and 55% overall yield from the corresponding carbazole precursor.
authors.affiliation: Department of Chemistry, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden (Germany), Fax: (+49) 351-463-37030.
authors.forename: Konstanze K
authors.initials: KK
authors.lastname: Julich-Gruner
authors.forename: Olga
authors.initials: O
authors.lastname: Kataeva
authors.forename: Arndt W
authors.initials: AW
authors.lastname: Schmidt
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Knölker
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis*; D001897:Boronic Acids / Q000737:chemistry*; D002227:Carbazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D011714:Pyrans; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D001897:Boronic Acids; D002227:Carbazoles; D011714:Pyrans; C041514:carbazole
keywords: CH bond activation; alkaloids; natural products; palladium; stereoselective catalysis