title: Enantioselective synthesis of (-)-dihydrocodeine and formal synthesis of (-)-thebaine, (-)-codeine, and (-)-morphine from a deprotonated α-aminonitrile.
abstract: The α-benzylation of a deprotonated bicyclic α-aminonitrile, followed by Noyori's asymmetric transfer hydrogenation combined with the Grewe cyclization onto a symmetrical A-ring precursor, are the key steps of a short and high-yielding enantioselective synthesis of the morphinan (-)-dihydrocodeine. This compound can be converted to (-)-thebaine in high yield by known transformations, while (-)-codeine and (-)-morphine are available from an advanced intermediate.
authors.affiliation: Institute of Organic Chemistry, Johannes Gutenberg University , Duesbergweg 10-14, 55128 Mainz, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Geffe
authors.forename: Till
authors.initials: T
authors.lastname: Opatz
mesh_terms: D003061:Codeine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D006865:Hydrogenation; D015394:Molecular Structure; D009020:Morphine / Q000138:chemical synthesis* / Q000737:chemistry; D009570:Nitriles / Q000737:chemistry*; D013237:Stereoisomerism; D013797:Thebaine / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D009570:Nitriles; D013797:Thebaine; D009020:Morphine; C014481:dihydrocodeine; D003061:Codeine