The ability of [2.2] paracyclophane to act as a neighboring group when attached to C, or Cp of a carbonium ion-forming system has been determined through reactivity comparisons of I, 11, I11 and IV. Solvolysis rate measurements and activation parameters demonstrated that the (2.2 lparacyclophanyl system is a better neighboring group in solvolytic reactions than its open-chain counterpart. Hydrolysis of optically pure bromide I in 80% dioxane20% water ...
