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.
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.
Kim
Hyoungsu
H
Department of Chemistry, Duke University, Durham, North Carolina 27708, USA.
Wooten
Ceshea M
CM
Park
Yongho
Y
Hong
Jiyong
J
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
D017605:Bromine Compounds; D017611:Fluorine Compounds; D005663:Furans; D017705:Lignans; D004986:Ether; D006859:Hydrogen; C507211:bromine trifluoride