title: Stereoselective synthesis of tetrahydrofuran lignans via BF(3) x OEt(2)-promoted reductive deoxygenation/epimerization of cyclic hemiketal: synthesis of (-)-odoratisol C, (-)-futokadsurin A, (-)-veraguensin, (+)-fragransin A(2), (+)-galbelgin, and (+)-talaumidin.
abstract: A versatile route to the synthesis of 2,5-diaryl-3,4-dimethyltetrahydrofuran lignans, (-)-odoratisol C (1), (-)-futokadsurin A (2), (-)-veraguensin (3), (+)-fragransin A2 (4), (+)-galbelgin (5), and (+)-talaumidin (6), is described. Central to the synthesis of the lignans is BF(3) x OEt(2)-promoted deoxygenation/epimerization of the hemiketal 9a followed by stereoselective reduction of the oxocarbenium ion intermediates 8a,b.
authors.affiliation: Department of Chemistry, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Hyoungsu
authors.initials: H
authors.lastname: Kim
authors.forename: Ceshea M
authors.initials: CM
authors.lastname: Wooten
authors.forename: Yongho
authors.initials: Y
authors.lastname: Park
authors.forename: Jiyong
authors.initials: J
authors.lastname: Hong
mesh_terms: D017605:Bromine Compounds / Q000737:chemistry*; D003500:Cyclization; D004986:Ether / Q000737:chemistry*; D017611:Fluorine Compounds / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D017705:Lignans / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D017605:Bromine Compounds; D017611:Fluorine Compounds; D005663:Furans; D017705:Lignans; D004986:Ether; D006859:Hydrogen; C507211:bromine trifluoride