34. Norbornanes Part 20 Inductivity and Bridging in 2-Norbornyl Cations

Article abstract of DOI:10.1002/hlca.19880710203

The solvolysis rates and products of several 1-substituted 2-exo- and 2-endo-norbornyl p-toluenesulfonates 7 and 8, respectively, have been determined.Hydrolyses of these epimeric tosylates yielded rearranged products in varying amounts, except when the substituent was COOCH3 or CN.The logarithms of the rate constants (log k) for the endo-series 8 correlated linearly with the corresponding inductive constants ?^q₁ with a reaction constant ρ₁ of -1.24.On the other hand, log k values for the exo-series 7 appear to fit two regression lines,the first line (ρ₁ = -1.90) defined by the tosylates that ionize, with rearrangement, to the tertiary cations 11, the second (ρ₁ = -1.86) by the tosylates 7(R = H, COOCH3, and CN) that ionize to an asymetrically bridged secondary cation 19.These results confirm the unique participation of C(6) with a ρ₁ of -2.00 in the ionization of 2-exo-norbornyl tosylate.