Diastereoselective construction of quaternary carbons directed via macrocyclic ring conformation: formal synthesis of (-)-mesembrine.
In this article, we report a highly diastereoselective new method for the generation of quaternary carbon centers through an anionic oxy-Cope/alkylation sequence where the diastereoselectivity is induced by the conformation of a macrocyclic tetrasubstituted enolate. The use of our methodology culminated in the formal total synthesis of (-)-mesembrine (34) in 11 steps from known starting materials.
Arns
Steve
S
Department of Chemistry, University of Ottawa, Ottawa, ON, Canada.
Lebrun
Marie-Eve
ME
Grisé
Christiane M
CM
Denissova
Irina
I
Barriault
Louis
L
D000478:Alkylation; D002244:Carbon / Q000737:chemistry*; D026121:Indole Alkaloids / Q000138:chemical synthesis*; D047028:Macrocyclic Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008968:Molecular Conformation; D013237:Stereoisomerism
D026121:Indole Alkaloids; D047028:Macrocyclic Compounds; D002244:Carbon; C011300:mesembrine