Selective synthesis of unsymmetrical ethers from different alcohols catalyzed by sodium bisulfite

An efficient method for the preparation of unsymmetrical ethers from alcohols catalyzed by sodium bisulfite is reported. The procedure enables the direct dehydration of primary, secondary, and tertiary benzylic alcohols with aliphatic alcohols in the absence of solvent to selectively produce unsymmetrical ethers in high yields with low catalyst loading. No symmetrical ethers are generated in the reactions. The etherification of a chiral secondary benzyl alcohol with butanol exclusively yields racemic ethers, suggesting that the reaction involves a carbocation intermediate mechanism.