Furan

__Characteristics__ Furan has a chemical formula of C4H4O. It is a heterocyclic organic compound consisting of a five membered aromatic ring with four carbon atoms and one oxygen.Furan is a colorless, flammable liquid with a boiling point near room temperature. It's soluble in organic solvents, but insoluble in water. It is very toxic and considered to be a carcinogen. It is manufactured by the copper-catayzed oxidation 1,3-butadiene. __History__ Furan derived its name from the word //furfur. Furfur//is a latin word meaning bran. It was initially prepared by Heinrich Lumpricht in 1870. ( he called it // tetraphenol) // The first furan was described by Carl Scheel in 1780 The derivative, furfual, was reported by Johan Dobereiner in 1831 It was then characterised nine years later by John Stenhuse (1838)

Chemistry Furan is aromatic because one of the lone pairs of electrons on the oxygen atom is delocalized into the ring, similar to benzene. Due to its aromaticity, furan's behavior is quite different to those that are more typically heterocyclic ethers

= Semiempirical SCF‐LCAO—MO Treatment of Furan = The self‐consistent field—molecular orbital method including configuration interaction is utilized for the study of the π‐electronic structure of the five‐membered heterocyclic molecule furan. The calculation proceeds through the density matrix formalism of McWeeny. A judicious choice of the two empirical core parameters for oxygen, along with the semiempirical approximations of Pariser and Parr, leads to a satisfactory description of the ionization potential, electronic spectra, and chemical reactivity of furan. **Hazards:** Furan in foods can form through multiple pathways that involve different naturally-present starting compounds that undergo thermal degradation or chemical rearrangement during food processing. The presence of furan in food is a potential concern because of indications of liver toxicity, including carcinogenicity, in experimental animals that were exposed to furan in their diet over a lifetime. The International Agency for Research on Cancer (IARC) has classified furan as possibly carcinogenic for humans.