of a solution of geraniol and (t-BuO)3Al in benzene with t-BuOOH at 5 °C gives (2R*, 3R*)-2,3-epoxy-3,7-dimethyl-6-octenyl acetate in 83% yield after acetylative workup. Eight allylic alcohols are converted to α,β-epoxy alcohols in preparative yields. The epoxidation of secondary (E)-allylic alcohols shows opposite stereoselectivities to t-BuOOH–VO(acac)2 system. Asymmetric epoxidation with a chiral
在 5 °C 下用 t-BuOOH 处理
香叶醇和 (t-BuO)3Al 在
苯中的溶液,得到 (2R*, 3R*)-2,3-epoxy-3,7-dimethyl-6-octenyl acetate in 83乙酰化处理后的 % 产率。八种
烯丙醇以制备产率转化为α,β-环
氧醇。仲 (E)-
烯丙醇的环
氧化显示出与 t-BuOOH-VO(acac)2 系统相反的立体选择性。用手性异羟
肟酸作为
配体的不对称环
氧化产生不令人满意的对映体过量程度。同样的系统也可以将仲醇以极好的收率转化为
酮,而伯醇反应非常缓慢。