水溶剂中芳醛与5,5-二甲基-1,3-环己二酮的反应

Reaction of Aromatic Aldehydes with 5,5-Dimethyl-1,3-cyclohexandione in Water

芳醛1与5,5-二甲基-1,3-环己二酮(2)在氯化三乙基苄基铵(TEBA)催化下在水中生成2,2’-芳亚甲基双(3-羟基-5,5-二甲基-2-环己烯-1-酮)(3),若在体系中有对甲苯磺酸存在时则生成3,3,6,6-四甲基-9-芳基-1,8-二氧代八氢化氧杂蒽(4)或3,3-二甲基-9-(3-羟基-5,5-二甲基-2-环己烯-1-酮-2-基)-1-氧代四氢化氧杂蒽(6)而不是生成3,产率接近定量。

The environmental friendly reaction of aromatic aldehydes with 5, 5-dimethyl-1,3-cyclohexandione giving 2,2'-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) (3) was carried out in water in the presence of trienthylbenzylammonium chloride (TEBA). While TsOH existed in the reaction, 3, 3, 6, 6-tetramethyl-9-aryl-1,8-dioxooctahydroxanthene (4) or 3,3-dimethyl-9-(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one-2-yl)-1-oxotetrahydroxanthene (6) rather than 3 was obtained with excellent yield.