Dehydration of alcohols over alumina: Effect of sodium impregnation on the mode of elimination

Dehydration of secondary alcohols has always been the key to studying reaction mechanisms of reactions catalyzed by oxides. The γ-alumina-promoted reactions always afforded a low S12 (1-olefin/2-olefin) and high Sct (Cis/trans). These were shown to proceed by the "anti" mode of elimination of elements of water. The effect of sodium impregnation has been studied, in detail, to understand the mode of elimination operative over these doped catalysts. Studies were conducted with 2-butanol and threo-3-methyl-2-pentanol over these catalysts. It appears that although sodium poisoning affected selectivity S12, it did not show any variation in Sct, suggesting no variation in the mode of elimination. The studies conducted with threo-3-methyl-2-pentanol confirm that only the anti mode of elimination is operative on these catalysts. © 1981.