Eleven new tetrahydrobenzo[b]pyran derivatives were synthesized via a three component reaction of different aromatic aldehydes, methyl cyanoacetate and 1,3-cyclohexadione, with water as solvent under catalyst-free microwave irradiation. The structures of all the new molecules were well analysed and their structures established by using various spectral techniques (1H NMR, 13C NMR, 15N NMR and HRMS). Various advantages of reported protocol are the ease of preparation, short reaction times (10 min), aqueous solvent and excellent yields (89–98%). Additionally, this method provides a clean access to the desired products by simple workup.

中文翻译：

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微波辐射下水的一锅法合成新的四氢苯并[b]吡喃

在无催化剂的微波辐射下，以水为溶剂，通过不同芳香醛，氰基乙酸甲酯和1,3-环己二酮的三组分反应，合成了十一种新的四氢苯并[b]吡喃衍生物。对所有新分子的结构进行了很好的分析，并使用各种光谱技术（1H NMR，13C NMR，15N NMR和HRMS）确定了它们的结构。所报道的方案的各种优点是易于制备，反应时间短（10分钟），水性溶剂和优异的收率（89-98％）。此外，此方法通过简单的后处理即可轻松获得所需产品。