The rates of hydrolysis of orthoesters, 2, 4, 10-trioxaadamantanes, substituted in position 3 (R= H, CH3, C2H5, C6H5) have been determined at 25 and 40° C in dioxane/water (60: 40 by volume). Substitution of hydrogen by the groups CH3, C2H5, and C6H5 shows clearly a decrease in rate: 0.018 (CH3), 0.014 (C2H5), and 0.003 (C6H5). This decrease, in accord with substituent effects, plus the strongly negative entropies of activation observed, ...
