MECHANISM OF HYDROLYSIS OF METHYL PSEUDO-8-AROYL-1-NAPHTHOATES IN AQUEOUS ACID

The hydrolyses of the methyl esters of pseudo-8-benzoyl-, -8-p-toluyl-, and -8-p-bromobenzoyl-1 -naphthoic acids have been studied in aqueous sulfuric and perchloric acid. The evidence unequivocally indicates that the hydrolyses proceed by a unimolecular mechanism involving an alkoxycarbonium ion. The criteria applied were: rate-acidity correlations (Zucker-Hammett, Bunnett w and φ), entropy of activation, deuterium oxide solvent isotope effect, and substituent effect. Exact values for methyl pseudo-8-benzoyl-1-naphthoate in H2SO4 are: slope of a plot of log kφ vs. -H0 = 1.07, w = -0.50, φ = -0.083, ΔS* = 0.7, and kH/kD = 0.36. The log kφ, for the hydrolysis of the three compounds in sulfuric acid correlates with σ+ and ρ = –2.1. © 1969, American Chemical Society. All rights reserved.