Tetrabutylammonium tribromide (TBATB)-promoted tetrahydropyranylation/depyranylation of alcohols

Alcohols are tetrahydropyranylated rapidly in high yields in the presence of a catalytic amount of TBATB in dichloromethane at room temperature. Depyranylation to their parent alcohol is achieved in quantitative yields by merely changing the solvent to methanol. (C) 2001 Elsevier Science Ltd. All rights reserved.