1,3-Elimination reactions of (3,4-epoxybutyl)stannanes. Approach to the synthesis of cycloeudesmol
作者:Louis Plamondon、James D. Wuest
DOI:10.1021/jo00006a019
日期:1991.3
The reactions that occur when stereochemically defined spirocyclic (3,4-epoxybutyl)stannanes are treated with C2H5AlCl2 depend critically on the relative orientation of tin, oxygen, and the three connecting atoms of carbon. A W arrangement of these atoms tends to favor formation of cyclopropanes by a concerted 1,3-elimination with inversion at both carbon centers. If this orientation cannot be achieved, cleavage of the epoxide occurs to give an ionic intermediate that can undergo a subsequent 1,3-elimination or a 1,2-shift of hydride promoted by an antiperiplanar carbon-tin bond.
RhI-Catalyzed Two-Component [(5+2)+1] Cycloaddition Approach toward [5-8-5] Ring Systems
Bringing it all together: [Rh(CO)2Cl}2]‐catalyzed two‐component [(5+2)+1] cycloaddition of ene‐vinylcyclopropanes with various tether types and substituents with CO has been designed for the one‐pot synthesis of fused tricyclic cyclooctenones with atom and step economies.