title: ZnCl2-mediated stereoselective addition of terminal alkynes to D-(+)-mannofuranosyl nitrones.
abstract: [reaction: see text] An optimized process for the addition of terminal alkynes to chiral nitrones using ZnCl2 and NEt3 in toluene is reported. The new reaction protocol is facile to perform and cost-effective. The resulting optically active propargyl N-hydroxylamines are isolated in good to excellent yield and high diastereoselectivity.
authors.affiliation: Laboratorium für Organische Chemie, ETH Hönggerberg, CH-8093 Zürich, Switzerland.
authors.forename: Dana
authors.initials: D
authors.lastname: Topić
authors.forename: Patrick
authors.initials: P
authors.lastname: Aschwanden
authors.forename: Roger
authors.initials: R
authors.lastname: Fässler
authors.forename: Erick M
authors.initials: EM
authors.lastname: Carreira
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D002712:Chlorides / Q000737:chemistry; D006898:Hydroxylamines / Q000138:chemical synthesis* / Q000737:chemistry; D008358:Mannose / Q000031:analogs & derivatives* / Q000737:chemistry*; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry*; D013237:Stereoisomerism; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D000480:Alkynes; D002712:Chlorides; D006898:Hydroxylamines; D009589:Nitrogen Oxides; D017967:Zinc Compounds; C015388:nitrones; C016837:zinc chloride; D008358:Mannose