Substituted benzodihydrofurans and benzodihydropyrans 2 were obtained by heating alcohol-phenols 1 in HMPA. New cyclic alkyl phenyl dimethylaminophosphoramidates 3 were also isolated. Their thermolysis was studied. This and other considerations show that bis(dimethylamino)phenol alkyl phosphorodiamidate 4 and by-product 3 are intermediates of an alternative two or threestep reaction pathway. This mechanistic
通过在HMPA中加热醇-
苯酚1获得取代的苯并二氢
呋喃和苯并二氢
吡喃2。还分离出新的环状烷基苯基二甲基
氨基膦酰胺酸酯3。研究了它们的热分解。这种和其他考虑表明,双(二甲基
氨基)
苯酚烷基二
氨基
氨基
磷酸酯4和副产物3是替代的两步或三步反应途径的中间体。这项机理研究为这种新型环脱
水方法的最佳实验条件的选择提供了指示。