The thermal addition reaction of various aroylketenes (C) generated by the thermolysis of 5-aryldioxofurans (A) to 1-aryl-1-trimethylsilyloxyethylenes gave 1, 5-diarylpentane-1, 3, 5-triones (D) and 2, 6-diaryl-4H-pyran-4-ones (E). The introduction of electron withdrawing substituents in the aroylketene and of electron donating substituents facilitated the addition reaction. The observed substituent effects and the reaction mechanism are interpreted in terms of molecular orbital analyses.
通过对5-芳基二氧
呋喃(A)的热分解生成的多种芳酰基酮(C)与1-芳基-1-三甲基
硅氧基
乙烯的热加成反应,生成了1, 5-二芳基
戊烷-1, 3, 5-三酮(D)和2, 6-二芳基-4H-
吡喃-4-酮(E)。在芳酰基酮中引入电子拉电子取代基以及在反应中引入电子给体取代基促进了加成反应。观察到的取代基效应和反应机制通过分子轨道分析进行了解释。