α,β-Unsaturated esters bearing a chiral oxazolidine or perhydropyrrolo[1,2-c]imidazole auxiliary at the β-position have been prepared and applied to the cycloadditions with N-metalated azomethine ylides derived from α-(benzylideneamino) esters. These reactions are found to proceed with an exclusively high diastereofacial selectivity to give 2,4-pyrrolidinedicarboxylates with four consecutive chiral
已经制备了在 β 位带有手性
恶唑烷或全氢
吡咯并 [1,2-c]
咪唑助剂的 α,β-不饱和酯,并将其应用于与衍生自 α-(亚苄基
氨基)酯的 N-
金属化偶氮甲碱叶立德的环加成反应。发现这些反应以独特的高非对映选择性进行,在去除手性助剂后得到具有四个连续手性中心的
2,4-吡咯烷二羧酸盐。讨论了过渡态的详细立体
化学。