The kinetics and mechanisms of the acid-catalysed hydrolysis of t-butyl formate in aqueous solution.

Abstract

The hydrolysis of t-butyl formate in aqueous acid solution has been studied over the range 35-83�. At low concentrations of catalysing acid, specific hydronium-ion catalysis is enhanced by the formic acid produced during the reaction. A series of oxygen-18 tracer experiments was performed, taking into account the formation of isobutylene, which is a by-product of hydrolysis by alkyl-oxygen fission. ��� The percentage alkyl-oxygen fission varies from 3 at 35� to 40 at 76�. Catalytic rate constants for reactions by the AAL1 and the AAC2 mechanisms are expressed respectively by the equations ���������������� k?1 = 1016.6exp(-28000/RT)�� 1. mole-1 sec-1���������������� k?2 = 107.8exp(-13600/RT)�� 1. mole-1 sec-1����������������� The rate constants found for the BAL1 mechanism are of order-of- magnitude significance only.