2,3-Dichloro-5,6-dicyano-p-benzoquinone as a Mild and Efficient Catalyst for the Tetrahydropyranylation of Alcohols

Hydroxy compounds readily add to 3,4-dihydro-2H-pyran under neutral conditions in the presence of a catalytic amount of 2,3-dichloro-5,6-dicyano-p-benzoquinone, to give high yields of the corresponding tetrahydropyranyl ethers.