2,3-Dihydropyran

Overview
2,3-Dihydropyran is the organic compound with the formula C5H8O. This cyclic ether is used to protect alcohols in organic synthesis. Dihydropyran is prepared by the dehydration of tetrahydrofurfuryl alcohol over alumina at 300-400 °C.
 * [[Image:Pyranprep.png|270px]]

Dihydropyran reacts with alcohols to form tetrahydropyranyl ethers. These ethers resist a variety of reactions, and the THP group can be removed with aqueous acid.