A cascade reaction of 4-hydroxythiocoumarin and 4Н-chromene-3-carbaldehydes was developed, consisting of Knoevenagel condensation and oxa-6π electrocyclization in the presence of ammonium acetate as catalyst. A series of polycyclic acetals containing a fused thiocoumarin moiety were obtained.

中文翻译：

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4-羟基硫代香豆素与4Н-铬烯-3-甲醛的正式[3 + 3]环加成反应：硫代色素[3'，4'：5,6]吡喃并[2,3- b] chromen-6-ones的合成

4- hydroxythiocoumarin和4所述的级联反应Н色烯-3- carbaldehydes被开发，在乙酸铵的存在下作为催化剂由Knoevenagel缩合和氧杂- 6πelectrocyclization的。获得一系列含有稠合的硫香豆素部分的多环缩醛。