An enviro-economic route for tosylation of alcohols and selective monotosylation of diols in good yield directly using p-toluenesulfonic acid together with metal-exchanged montmorillonite instead of p-toluenesulfonyl chloride or p-toluenesulfonic anhydride is described. The Fe3+-montmorillonite clay is the most effective catalyst among metal- exchanged montmorillonites for such tosylation reactions. The activity follows the ...