An Approach to the Imine Ring System of Pinnatoxins
摘要:
A concise stereoselective approach to the spirobicyclic imine fragment of pinnatoxins and pteriatoxins is described. The approach relies on a tandem reaction sequence involving consecutive sigmatropic rearrangements to build the quaternary chiral center at the core of the spirobicyclic ring system.
TiCl(4), PhI(OAc)(2), or CuCl(2) as an oxidant. The stereoselectivity can be explained by a radical coupling mechanism. Optically active dibenzylbutyrolactone lignans, such as (-)-hinokinin and (-)-dimethylmatairesinol, and dibenzylbutanediol lignans, such as (-)-dihydrocubebin and (-)-dimethylsecoisolariciresinol, were synthesized from the major R,R-dimers. The oxidative coupling of (4R, 5S)-1-(3-arylpropanoyl)-3
An Approach to the Imine Ring System of Pinnatoxins
作者:Matthew J. Pelc、Armen Zakarian
DOI:10.1021/ol050321l
日期:2005.4.14
A concise stereoselective approach to the spirobicyclic imine fragment of pinnatoxins and pteriatoxins is described. The approach relies on a tandem reaction sequence involving consecutive sigmatropic rearrangements to build the quaternary chiral center at the core of the spirobicyclic ring system.
SYNTHESIS OF (2R,3R)-2,3-DIMETHYL-1,4-BUTANEDIOL BY OXIDATIVE HOMOCOUPLING OF (4S)-ISOPROPYL-3-PROPIONYL-2-OXAZOLIDINONE
作者:Lu, Chong-Dao、Zakarian, Armen、Brak, Katrien、Ellman, Jonathan A.