Despite the rapid growth of enantioselective halolactonization reactions in recent years, most are effective only when forming smaller (6,5,4-membered) rings. Seven-membered ε-lactones, are rarely formed with high selectivity, and never without conformational bias. We describe the first highly enantioselective 7-exo-trig iodolactonizations of conformationally unbiased ε-unsaturated carboxylic acids, effected by an unusual combination of a bifunctional BAM catalyst, I₂, and I(III) reagent (PhI(OAc)₂:PIDA).

中文翻译：

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高价碘对映选择性碘内酯化制备 ε-内酯环

尽管近年来对映选择性卤内酯化反应迅速增长，但大多数仅在形成较小的（6,5,4-元）环时才有效。七元 ε-内酯很少以高选择性形成，而且从来没有没有构象偏差。我们描述了第一个高度对映选择性的 7 - exo -trig iodolactonizations 构象无偏的 ε-不饱和羧酸，由双功能 BAM 催化剂、I ₂和 I( III ) 试剂 (PhI(OAc) ₂ :PIDA)的不寻常组合影响.