A mild, chemoselective and convenient method for the formation and deprotection of tetrahydropyranyl ethers is described. With 1-5 mol% of acetyl chloride and slightly excess dihydropyran in methylene chloride or in neat dihydropyran, the formation of THP ethers from the corresponding alcohols was accomplished in the presence of many acid-sensitive functional groups. Efficient cleavage of THP ethers was also accomplished with the same reagent by switching the solvent to methanol.