<unk> , also known as<unk> e and furfuran, is a heterocyclic organic compound.  It is typically derived by the thermal decomposition of pentose-containing materials,  cellolosic solids especially pine-wood.<unk>  is a colorless, flammable, highly volatile liquid with a boiling point close to room temperature.  It is toxic and may be carcinogenic. Catalytic hydrogenation (see redox) of<unk>  with a palladium catalyst gives tetrahydrofuran.<unk>  is aromatic because one of the lone pairs of electrons on the oxygen atom is delocalized into the ring, creating a 4n+2 aromatic system (see Hückel's rule) similar to benzene.  Because of the aromaticity, the molecule is flat and lacks discrete double bonds. The other lone pair of electrons of the oxygen atom extends in the plane of the flat ring system.  The sp2 hybridization is to allow one of the lone pairs of oxygen to reside in a p orbital and thus allow it to interact within the pi-system.
The name<unk>  comes from the Latin furfur, which means bran. The first<unk>  derivative to be described was 2-furoic acid, by Carl Wilhelm Scheele in 1780. Another important derivative, furfural, was reported by Johann Wolfgang Döbereiner in 1831 and characterised nine years later by John Stenhouse.<unk>  itself was first prepared by Heinrich Limpricht in 1870, although he called it tetraphenol.
Furan
Vinyl ether
Lime 
Oxoacid
Starch
Oxamyl
Acyl
Cyclohexane