Tetrahydrofuran is a compound consisting of four carbons and one oxygen connected in a ring formation to form a cyclic ether. It is a colorless, organic solvent of low viscosity. Because it is of mid-range polarity and miscible with water, it has diverse use as a solvent.
It is often used in research laboratories as a synthetic precursor to organic compounds, as a solvent for organic synthesis, and in reversed-phase chromatography solvent systems. It is especially useful in the polymer industry due to its ability to solubilize polyvinylchloride. It is also used as a pretreatment solvent for biomass due to its ability to solubilize/delignify lignocellulose towards the production of biofuel. It is most commonly produced via the acid-catalyzed dehydration of 1,4-butanediol.