title: Enantioselective Cyclopropanation with α-Alkyl-α-diazoesters Catalyzed by Chiral Oxazaborolidinium Ion: Total Synthesis of (+)-Hamavellone B.
abstract: Chiral oxazaborolidinium ion-catalyzed asymmetric cyclopropanation of α- or α,β-substituted acroleins with α-alkyl-α-diazoesters has been developed. With this methodology, chiral functionalized cyclopropanes containing a quaternary stereogenic center were obtained with high to excellent enantioselectivities (up to >99% ee). The synthetic utility of optically enriched functionalized cyclopropane was demonstrated in the first total synthesis of (+)-hamavellone B, which establishes the absolute configuration of natural (+)-hamavellone B.
authors.affiliation: Department of Chemistry, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Su Yong
authors.initials: SY
authors.lastname: Shim
authors.affiliation: Department of Chemistry, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Jae Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Western Seoul Center, Korea Basic Science Institute , Seoul 120-140, Korea.
authors.forename: Miso
authors.initials: M
authors.lastname: Nam
authors.affiliation: Western Seoul Center, Korea Basic Science Institute , Seoul 120-140, Korea.
authors.forename: Geum-Sook
authors.initials: GS
authors.lastname: Hwang
authors.affiliation: Department of Chemistry, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Ryu
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D003521:Cyclopropanes; C000607875:hamavellone B