A Simple and Efficient Synthesis of 2-Methyl-2-trifluoromethylchroman-4-ones from 2-Trifluoromethyl-4<i>H</i>-chromen-4-imines and Malonic Acid
作者:Vyacheslav Ya. Sosnovskikh、Boris I. Usachev
DOI:10.1055/s-2002-35233
日期:——
N-Benzyl-2-trifluoromethyl-4H-chromen-4-imines and malonic acid on heating in anhydrous dioxane afford 2-trifluoromethyl-2-methylchroman-4-ones in ∼60% yield. 2-Methyl-2-trifluoromethyl-4-oxochromane-6-carbaldehyde and 2-methyl-2-trifluoromethyl-4-oxochromane-6-carboxylic acid, the fluorinated analogues of natural lactarochromal and the corresponding acid, were obtained by the oxidation of 2,6-dimethyl-2-trifluoromethylchroman-4-one with K2S2O8.
在无水二噁烷中加热 N-苄基-2-三氟甲基-4H-苯并吡喃-4-亚胺和丙二酸,可得到 2-三氟甲基-2-甲基苯并吡喃-4-酮,收率为 60%。用 K2S2O8 氧化 2,6-二甲基-2-三氟甲基苯并二氢吡喃-4-酮,得到 2-甲基-2-三氟甲基-4-氧代苯并二氢吡喃-6-甲醛和 2-甲基-2-三氟甲基-4-氧代苯并二氢吡喃-6-羧酸,它们是天然苯并二氢吡喃的氟化类似物和相应的酸。