The reaction of 5,5-dimethyl-1,3-cyclohexanedione (dimedone) with various aromatic aldehydes catalyzed by tamarind water produces 2,2ʹ-arylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives in 85-98% yield under water bath heating at 60°C. Xanthene derivatives as cyclized products have not been obtained by this procedure. This method provides several advantages such as environmental friendliness, high yields and simple work-up procedure. The product is purified by simple filtration followed by crystallization with ethanol and drying processes.

中文翻译：

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罗望子水催化2,2′-芳基亚甲基双（3-羟基-5,5-二甲基-2-环己烯-1-酮）衍生物的改进合成：一种绿色方法

罗望子水催化5,5-二甲基-1,3-环己二酮（二甲酮）与各种芳香醛反应生成2,2′-芳基亚甲基双（3-羟基-5,5-二甲基-2-环己烯-1-酮）在60℃水浴加热下，其衍生物的收率为85-98％。该方法尚未获得作为环化产物的吨衍生物。该方法具有许多优点，例如环境友好，产率高和后处理程序简单。产物通过简单的过滤纯化，然后用乙醇结晶并干燥。