The Substituent Effect. I. Normal Substituent Constants from the Hydrolysis of Substituted-benzyl Benzoates

The rates of the alkaline hydrolyses of 24 m- and p-substituted-benzyl benzoates were measured in 70% (v/v) aqueous acetone at 25°C. The given set of σ0 constants was precisely identical with our standard set derived from m- and p-substituted ethyl phenylacetates. The general utility of σ0 constants is demonstrated for unexalted and exalted resonance reactivities as the reference scale in our LArSR equation: logk⁄k0=ρ(σ0+r+Δσ+R+r−Δσ−R)