Organolithium reagents undergo highly regio- and diastereoselective 1,4-addition to (S,S)-(+)-pseudoephedrine enamides furnishing the corresponding β-alkyl-substituted adducts in excellent yields and diastereoselectivities. In addition, the intermediate lithium enolates generated after the conjugate addition step undergo a highly diastereoselective alkylation reaction, furnishing α,β-dialkyl-substituted
有机锂试剂对(S,S)-(+)-伪
麻黄碱酰胺进行高度的区域和非对映选择性1,4-加成,从而以优异的收率和非对映选择性提供相应的β-烷基取代的加合物。另外,在共轭加成步骤之后产生的中间烯醇
锂经历高度非对映选择性烷基化反应,以高收率提供α,β-二烷基取代的酰胺。使用非常简单和高产率的方法,将获得的加合物转化为手性非外消旋的β-烷基和α,β-二烷基取代的
羧酸以及γ-烷基和β,γ-二烷基取代的醇。