The dehydration of t-butyl alcohol catalyzed by sulfonic acid resin

Abstract

Rates of t-butyl alcohol dehydration catalyzed by beads of sulfonic acid resin suspended in liquid reactant were measured at temperatures between 35 and 77 °C. Catalytically active -SO 3H groups were diluted by partial replacement with -SO 3Na, -SO 3K, and -SO 3Rb groups. The order of reaction in -SO 3H group concentration increased from 1 to about 4 as concentration increased 20-fold. The kinetics at low -SO 3H group concentrations indicate a carbonium ion mechanism and at high concentrations a concerted mechanism with t-butyl alcohol hydrogen-bridged in a network of -SO 3H groups. Rates of reaction catalyzed by variously crosslinked resins and by p-toluenesulfonic acid in solution are consistent with this interpretation.