Introduction of sulfonated rice husk ash as a highly efficient reusable catalyst for the protection of the hydroxyl group

A mild, efficient and fast method for the trimethylsilyl (TMS), tetrahydropyranyl (THP) and methoxymethyl (MOM) protection of alcohols and phenols in the presence of sulfonated rice husk ash (RHA-SO3H) is reported. All reactions were performed at room temperature in high to excellent yields. All the products are separated and compared with authentic samples and/ or identified using different types of methods including FT-IR, 1H NMR and 13C NMR spectroscopy. Ease of the preparation and handling of the catalyst, heterogeneous reaction conditions, reusability of the catalyst, easy work-up procedure and short reaction times are the main advantages of this method, which make this procedure useful and attractive addition to the available methods.