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 A_AL1 and the A_AC2 mechanisms are expressed respectively by the equations                  k?₁ = 10^16.6exp(-28000/RT)   1. mole^-1 sec^-1                 k?₂ = 10^7.8exp(-13600/RT)   1. mole^-1 sec^-1                  The rate constants found for the B_AL1 mechanism are of order-of- magnitude significance only.