Double-Tandem [4_π+2_π]·[2_π+2_π]·[4_π+2_π]·[2_π+2_π] Synthetic Sequence with Photoprotolytic Oxametathesis and Photoepoxidation in the Chromone Series

Chromones are introduced into a double-tandem [4π+2π]·[2π+2π]·[4π+2π]·[2π+2π] synthetic sequence, culminating in photoprotolytic oxametathesis, which leads to an expeditious growth of molecular complexity over a few experimentally simple steps. The overall reaction can potentially be utilized in diversity-oriented synthesis, as it allows for three or more diversity inputs furnishing novel unique polycyclic scaffolds decorated with a variety of functionalities and aromatic/heterocyclic pendants. The polycyclic alkenes, resulting from the oxametathesis step, were found to undergo efficient and clean photoinduced epoxidation when irradiated in the presence of molecular oxygen.色酮（Chromones）被引入双串联[4π+2π]·[2π+2π]·[4π+2π]·[2π+2π]合成序列，该序列最终以光质子解型氧杂复分解反应收尾，可通过数步实验操作简便的步骤，高效构建分子复杂度。该整体反应有望应用于多样性导向合成（diversity-oriented synthesis），因其可容纳三个及以上的多样性输入位点，能够生成带有多种官能团与芳香/杂环侧链取代基的新型独特多环骨架。研究表明，由氧杂复分解步骤生成的多环烯烃，在分子氧存在下辐照时，可发生高效且无副反应的光诱导环氧化反应。