The reaction of (2, 6-dimethylphenyl) diphenylmethylenephosphine (1) with tetrachloro-o- benzoquinone (2), 3, 5-di-t-butyl-o-benzoquinone (3) and phenanthrenequinone (4) yielded the formal [2+ 4] cycloaddition products 5, 14 and 19, respectively. In the given order, the rate of reaction and the formation of 1: 2 adducts decreased. With 2 equivalents of the orthoquinones, the 1.2 adducts were the only products observed. The mechanism of the ...
![2-(2,6-dimethylphenyl)-3,3-diphenyl-2,3-dihydrophenanthro[9,10-e][1,4,2]dioxaphosphinine Structure](https://image.chemsrc.com/caspic/219/89291-12-3.png)
![hydroxy-[(10-hydroxyphenanthren-9-yl)oxy-diphenylmethyl]-oxophosphanium Structure](https://image.chemsrc.com/caspic/143/89291-14-5.png)
