Lithium triflate (LiOTf) catalyzed efficient and chemoselective tetrahydropyranylation of alcohols and phenols under mild and neutral reaction conditions

Different types of alcohols and phenols were effectively converted to the corresponding THP ethers in the presence of DHP and a catalytic amount of lithium trifluoromethanesulfonate (LiOTf) in refluxing 1,2-dichloroethane under essentially neutral reaction conditions. The method also shows good chemoselectivity for mono-tetrahydropyranylation of symmetrical diols.