Abstract The displacement rate of aryloxy substituents by methoxide ions in the following triphosphites: 2-phenoxy-1, 3, 2-dioxaphospholane (I), 2-methoxy-benz-1, 3, 2- dioxaphospholene (II), and dimethyl phenylphosphite (III), is for each phosphite higher in methanol than in dichloromethane. On the other hand, dichloromethane discriminates much more strongly between five-membered cyclic and acyclic phosphites than methanol, as ...