A Lewis acid‐catalyzed formal [3+3] cascade annulation strategy for the formation of diverse tricyclic compounds possessing functionalized pyrano[3,2‐c]chromen‐5(2H)‐one fragments has been developed using propargylic alcohols and 4‐hydroxy‐2H‐chromen‐2‐ones as the substrates. The protocol provides a one‐step, environmentally benign method of accessing a broad range of pyrano[3,2‐c]chromen‐5(2H)‐one derivatives in excellent yields under mild conditions and with good functional‐group tolerance. The method is effective on the gram scale, which highlights the inherent practicality of this synthetic transformation.

中文翻译：

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Lewis酸催化的4-羟基-2H-铬原子-2-酮与丙醇的形式[3 + 3]环化

一种路易斯酸催化的正式[3 + 3]级联环化策略，用于形成具有官能化吡喃并[3,2-c] chromen-5（2 H）-一个片段的各种三环化合物，已使用炔丙醇和4-羟基2 H-铬2-2作为底物。该协议提供了一种在环境温和的条件下以良好的收率和良好的官能团耐受性来访问范围广泛的吡喃并[3,2-c] chromen-5（2 H）-one衍生物的一步法，对环境无害的方法。该方法在克规模上是有效的，这突出了这种合成转化的固有实用性。