Solid silica-based sulfonic acid as an efficient and recoverable interphase catalyst for selective tetrahydropyranylation of alcohols and phenols

Various types of alcohols and phenols are converted to the corresponding tetrahydropyranyl (THP) ether using a catalytic amount of solid silica-based sulfonic acid. The catalyst shows high thermal stability (up to 300 °C) and can be recovered and reused for at least eight treaction cycles without loss of reactivity.