Protection of aldehydes by formation of the corresponding dimethyl acetals and protection of alcohols and phenols by formation of the corresponding tetrahydropyranyl ethers have been carried out successfully using ITQ-2 zeolite as acid catalyst. Its catalytic activity for these reactions is compared with those obtained with MCM-22, Beta zeolites, and the mesoporous aluminosilicate MCM-41, all of them with similar Si/Al ratios. The results obtained indicate that when the reactions involve bulky reactants, ITQ-2 shows, in all cases, the highest activity as a consequence of the combination of its delaminated structure and the presence of strong acid sites.