Selective deprotection of terminal isopropylidene acetals and trityl ethers using HClO4 supported on silica gel

Terminal isopropylidene acetals are selectively cleaved to the corresponding 1,2-diols in good to excellent yields in 6–24 h at room temperature by using the ‘HClO4·SiO2’ reagent system. Likewise, trityl ethers are readily cleaved to the corresponding alcohols in good to excellent yields within 2–3 h at room temperature. Work-up involves merely filtration of the reagent followed by purification of the crude product.