Structure of Tetrahydrofuran

Tetrahydrofuran is abbreviated THF. THF is a very common ether solvent. Note that the 5-membered ring is not planar so that the CH bonds are less eclipsing. The only symmetry element that is left is a twofold axis through the O-atom and the midpoint of the bond opposite to the oxygen.


Figure. The RHF/6-31G* optimized structure of tetrahydrofuran (THF). This structure contains a twofold axis and this structure is the most stable structure of THF.