(4) For example, the anion of 2, X= H, in tetrahydrofuran was heated to-60'in the presence of potassium &butoxide, tertiary amines, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide, or lithium chloride, and, at best, only a 30% yield of 1, l- diphenylethylene was obtained, together with benzophenone, unsaturated phosphonate, and acidic materials. The slowness of elimination from the anion of 2, X= H, relative to 2, X ...
