title: Enantiocontrolled synthesis of (-)-9-epi-pentazocine and (-)-aphanorphine.
abstract: We have developed novel asymmetric routes to (-)-9- epi-pentazocine and (-)-aphanorphine from a d-tyrosine derivative. The tricyclic frameworks of (-)-9- epi-pentazocine and (-)-aphanorphine were assembled stereoselectively via intramolecular Friedel-Crafts reaction of the corresponding bicyclic precursors, generated with titanium-promoted enyne cyclization and indium-initiated atom-transfer radical cyclization, respectively.
authors.affiliation: Laboratory of Modern Synthetic Organic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Xiaobao
authors.initials: X
authors.lastname: Yang
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhai
authors.forename: Zhong
authors.initials: Z
authors.lastname: Li
mesh_terms: D001952:Bridged-Ring Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D015394:Molecular Structure; D010423:Pentazocine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001952:Bridged-Ring Compounds; D011758:Pyrroles; C434304:aphanorphine; D010423:Pentazocine