Electrophilic Cyclization and Intermolecular Acetalation of 2‑(4-Hydroxybut-1-yn-1-yl)benzaldehydes: Synthesis of Diiodinated Diepoxy­dibenzo­[<i>c</i>,<i>k</i>]­[1,9]­dioxacyclo­hexa­decines

An expedient strategy for the preparation of diiodinated diepoxy­dibenzo­[c,k]­[1,9]­dioxa­cyclo­hexadecines from readily available 2-(4-hydroxybut-1-yn-1-yl)­benzaldehydes through electrophile-triggered tandem cyclization/intermolecular acetalation sequence has been presented. The electrophilic macrocyclization can be performed under mild conditions and in up to gram quantities. Moreover, palladium-catalyzed coupling and reduction reactions of the resulting iodides could efficiently afford oxa-macrocycles.本研究报道了一种以易得的2-(4-羟基丁-1-炔-1-基)苯甲醛为原料，通过亲电试剂诱导的串联环化/分子间缩醛化序列，制备二碘代二环氧二苯并[c,k][1,9]二氧杂环十六碳烯的便捷策略。该亲电大环化反应可在温和条件下进行，且可放大至克级规模。此外，所得碘代物可通过钯催化偶联与还原反应高效转化为氧杂大环化合物。