A one-pot method for the selective synthesis of two isomers 4H-chromene and 2,8-dioxabicyclo[3.3.1]nonane derivatives was developed without a catalyst and using EtOH/H₂O (4:1, v/v) as the solvent. The reaction was conducted under mild conditions, with forming multiple chemical bonds in one pot and high atom economy, and only a stoichiometric amount of H₂O is produced as the byproduct. Its selectivity was controlled by thermodynamics and kinetics, and the reasons for the transformation of the two structures are also discussed.

中文翻译：

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无催化剂条件下两种异构体4H-色烯和2,8-二氧杂双环[3.3.1]壬烷衍生物的可控合成

开发了一种选择性合成两种异构体 4 H -色烯和 2,8-二氧杂双环 [3.3.1] 壬烷衍生物的一锅法，无需催化剂，使用 EtOH/H ₂ O (4:1, v/v)作为溶剂。该反应在温和的条件下进行，一锅形成多个化学键，原子经济性高，副产物仅产生化学计量的H ₂ O。其选择性受热力学和动力学控制，并讨论了两种结构发生转变的原因。