Opening of Aryl-Substituted Epoxides To Form Quaternary Stereogenic Centers: Synthesis of (−)-Mesembrine
作者:Douglass F. Taber、Yigang He
DOI:10.1021/jo0511039
日期:2005.9.1
are easily converted into aryl-substituted cyclic alkenes by the addition of an aryl Grignard reagent followed by dehydration. These alkenes are good substrates for asymmetric epoxidation. We have found that the addition of allylic and benzylic Grignard reagents can occur preferentially at the benzylic position of the derived epoxides to give the quaternary stereogenic center. This approach led to a