Brønsted Acidic Ionic Liquids: Fast, Mild, and Efficient Catalysts for Solvent‐Free Tetrahydropyranylation of Alcohols

Abstract Bronsted acidic ionic liquids as efficient and reusable catalysts for the protection of alcohols as tetrahydropyranyl (THP) ethers under solvent‐free conditions at room temperature was investigated. Good to excellent yields were obtained at a faster rate over [BMIm][HSO4] or [BMIm][H2PO4].