The asymmetric synthesis of 4-nitrocyclohexanone derivatives has been accomplished by enantioselective double Michael additions of γ,δ-unsaturated β-ketoesters to nitroalkenes using a catalytic amount of bifunctional thiourea and TMG. The three contiguous stereogenic centers of the obtained products were constructed with good to high diastereoselectivity and up to 92% ee. The biologically active natural
通过使用催化量的双官能
硫脲和
TMG将γ,δ-不饱和β-
酮酸酯对映选择性双迈克尔加成到硝基烯烃中来完成4-硝基
环己酮衍
生物的不对称合成。所获得产物的三个连续的立体异构中心的构建具有良好至高的非对映选择性和高达92%的ee。具有
生物活性的
天然产物(-)-依巴替丁(Epibatidine)由中间体11a分七个步骤合成,总产率为30%。