title: Total synthesis of (+)-yohimbine via an enantioselective organocatalytic Pictet-Spengler reaction.
abstract: The binolphosphoric acid-catalyzed Pictet-Spengler reaction of an N-(5-oxy-2,4-pentadienyl)tryptamine derivative with methyl 5-oxo-2-(phenylseleno)pentanoate leads to the tetrahydro-β-carboline in a 92:8 enantiomeric ratio. This product is easily converted into the substrate for a stereoselective intramolecular Diels-Alder reaction of the type earlier reported by Jacobsen. These two key steps constitute the basis for a nine-step total synthesis of (+)-yohimbine from tryptamine. A similar asymmetric Pictet-Spengler reaction was applied to the synthesis of an intermediate in the recent total synthesis of corynantheidine by Sato.
authors.affiliation: Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Bart
authors.initials: B
authors.lastname: Herlé
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Wanner
authors.forename: Jan H
authors.initials: JH
authors.lastname: van Maarseveen
authors.forename: Henk
authors.initials: H
authors.lastname: Hiemstra
mesh_terms: D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D013237:Stereoisomerism; D014363:Tryptamines / Q000737:chemistry*; D015016:Yohimbine / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D014363:Tryptamines; D015016:Yohimbine