Functionalization and Utility of Bridging Ethers in the Transformations of Bicyclo[5.4.0]undecanes
作者:David R. Williams、John W. Benbow、John G. McNutt、Eric E. Allen
DOI:10.1021/jo00109a013
日期:1995.2
Studies detail the formation and utility of bridged ethers of bicyclo[5.4.0]undecanes as a means for stereocontrolled functionalization as described in a survey of conjugate additions, reductions, and oxidative cyclizations. The intramolecular dipolar cycloaddition of 3-oxidopyrylium ylides affords a facile preparation of the starting trans-fused bicyclo[5.4.0]undecenone 1. Efficient methods toward highly oxygenated bicycloundecanes are described via the highly selective reductive cleavage of 12-oxatricyclo[6.3.1.0(1,6)]dodecanes such as 20 and 21. Reclosure of the era-bridge was examined. Vanadium-catalyzed oxidative reclosure of 24 led exclusively to the novel 2-oxatricyclo[5.4.1.0(3,8)]dodecane system 31.