A method for the preparation of methyl 4-hydroxy-2-(trifluoromethyl)-4H-chromenes-3-carboxylate derivatives 3a–j from readily available trifluoromethylated building block methyl (Z)-2-bromo-4,4,4-trifluoro-2-butenoate 1 was described. Treatment of 3a–j with Sarrett reagent in CH2Cl2 generated methyl 4-oxo-2-(trifluoromethyl)-chromene-3-carboxylate derivatives 4a–h with moderate to good yields, which
一种由容易获得的三
氟甲基化的结构单元甲基(Z)-2-
溴-4,4,4-制备
4-羟基-2-(三
氟甲基)-4 H-苯甲基-3-
羧酸甲酯3a – j的方法描述了三
氟-
2-丁烯酸酯1。在CH 2 Cl 2中用Sarrett试剂处理3a – j生成4-氧代-2-(三
氟甲基)-亚甲基-3-
羧酸甲酯衍
生物4a – h,具有中等至良好的产率,可以将其转化为2-三
氟甲基取代的通过
环丙烷化和
路易斯酸催化的开环反应制备多功能苯并氧杂庚环。