The enolates of cyclic β-ketoesters react with electrophilic acetylenes to give the corresponding Michael adducts in good yields when the reaction is performed in acetone in the presence of catalytic amounts of K2CO3. The Michael adducts resulting from ethynylmethylketone, when refluxed in toluene in the presence of catalytic amounts of pTsOH, undergo an intramolecular aldol reaction leading mainly
当在
丙酮中在催化量的K 2 CO 3存在下进行反应时,环状β-
酮酸酯的烯醇化物与亲电子
乙炔反应,以高收率得到相应的迈克尔加合物。由
乙炔基甲基酮产生的迈克尔加合物,在催化量的pTsOH存在下在
甲苯中回流时,会发生分子内羟醛反应,主要导致双环[n。OH]。3. 1]除罗宾逊环化产物外的链二烯酮。