6566-25-2Relevant articles and documents
Kinetics of Hydrolysis of 1-Acetoxy-, 1-Acetoxy-8-hydroxy-, and 1,8-Diacetoxynaphthalenes; Intramolecular Participation by a Hydroxy Group
Hibbert, Frank,Spiers, Karen J.
, p. 571 - 574 (1988)
Consecutive hydrolysis of the acetoxy groups in 1,8-diacetoxynaphthalene in aqueous alkaline solution can be studied kinetically because hydrolysis occurs more rapidly for the diacetate than for 1-acetoxy-8-hydroxynaphthalene which is mostly present in the ionised form.The dependence of the rate coefficient (k2) for hydrolysis of 1-acetoxy-8-hydroxynaphthalene on the concentration of hydroxide ion is complex because of the equilibrium between the ionised and un-ionised forms and their different reactivities.The equilibrium between the ionised and un-ionised forms has been measured separately and the data are combined with the kinetic results to show that the linear dependence of k2 on -> at high concentrations is due to reaction of the ionised form with OH-.At low concentrations, the curved dependence of k2 on -> can be explained by reaction of ionised 1-acetoxy-8-hydroxynaphthalene with solvent.The value of the rate coefficient (k4) for this reaction, in comparison with the value for the reaction of 1-acetoxynaphthalene with water, shows that the hydroxy group assists the attack of water by intramolecular general base catalysis.A kinetic solvent isotope effect K4(H2O)/k4(D2O) 2.2 +/- 0.5 is observed.
