title: Synthesis of (+)-Ipalbidine Based on 6-exo-trig Radical Cyclization of a β-Amino Radical.
abstract: N-Boc (S)-proline was converted into (2S)-2-[(phenylselanyl)methyl]pyrrolidine, which was alkylated on nitrogen with 2-bromo-1-(4-methoxyphenyl)ethan-1-one. Reaction with vinyllithium, 6-exo-trig radical cyclization (Bu3SnH, AIBN, PhMe, 110 °C), dehydration (P2O5, H3PO4), and demethylation (BBr3) gave (+)-ipalbidine with ee >99%.
authors.affiliation: Chemistry Department, University of Alberta , Edmonton, Alberta T6G 2G2, Canada.
authors.forename: JongMyoung
authors.initials: J
authors.lastname: Chea
authors.affiliation: Chemistry Department, University of Alberta , Edmonton, Alberta T6G 2G2, Canada.
authors.forename: Derrick L J
authors.initials: DL
authors.lastname: Clive
mesh_terms: D000478:Alkylation; D000588:Amines / Q000737:chemistry*; D003500:Cyclization; D004980:Ethane / Q000031:analogs & derivatives / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry*; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D016566:Organoselenium Compounds; D011392:Proline / Q000737:chemistry*; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C000606230:2-((phenylselanyl)methyl)pyrrolidine; C000606231:2-bromo-1-(4-methoxyphenyl)ethan-1-one; D000588:Amines; D005609:Free Radicals; D007212:Indolizines; D016566:Organoselenium Compounds; D011759:Pyrrolidines; C057484:ipalbidine; D011392:Proline; D004980:Ethane