The synthesis of the corresponding epoxides 2 and 4 by epoxidation of aurones (2-benzylidenebenzofuran-3(2H)-ones, 1) and isoflavones (3-aryl-4H-1-benzopyran-4-ones,3) with dimethyldioxirane at subambient temperatures is reported. These acid- and base-sensitive epoxides, which have been previously difficult to prepare, were isolated in excellent yields and were completely characterized by spectral and microanalytical data. The now readily available aurone and/or isoflavone oxides may serve as convenient precursors to flavonoid-type natural products.
报告了在低于环境温度下,通过将
黄酮(2-亚苄基
苯并呋喃-3(2H)-酮,1)和异
黄酮(3-芳基-4H-1-苯并
吡喃-4-酮,3)与二甲基二氧杂
环戊烯环氧化,合成相应的环氧物2和4。这些对酸和碱敏感的环氧物以前很难制备,但此次分离的收率很高,并通过光谱和微量分析数据得到了完全表征。现在容易获得的
黄酮和/或异
黄酮氧化物可以作为黄
酮类天然产物的便捷前体。