Furan, also known as furane and furfuran, is a heterocyclic organic compound, produced when wood, especially pine-wood, is distilled. Furan is a clear, colorless, very volatile and highly flammable liquid with a boiling point close to room temperature. It is toxic and may be carcinogenic. Catalytic hydrogenation (see redox) of furan with a palladium catalyst gives tetrahydrofuran. IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article does not cite its references or sources. ... The molecular mass (abbreviated MM) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture with air. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Chemical structure of furan selfmade by cacycle File links The following pages link to this file: Furan Categories: GFDL images ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... Pyridine a simple heterocyclic compound Heterocyclic compounds are organic compounds which contain a ring structure containing atoms in addition to carbon, such as sulfur, oxygen or nitrogen, as part of the ring. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy... The ability of a liquid to evaporate quickly and at relatively low temperatures. ... Flammable or Flammability refers to the ease at which a substance will ignite, causing fire or combustion. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... Toxic redirects here, but this is also the name of a song by Britney Spears; see Toxic (song) Look up toxic and toxicity in Wiktionary, the free dictionary. ... In pathology, a carcinogen is any substance or agent that promotes cancer. ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... General Name, Symbol, Number palladium, Pd, 46 Chemical series transition metals Group, Period, Block 10, 5, d Appearance silvery white metallic Standard atomic weight 106. ... It has been suggested that this article or section be merged into Catalysis. ... For other uses of THF, see THF (disambiguation) Tetrahydrofuran is a heterocyclic organic compound. ...

Furan 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. This aromatic system forms two rings of electrons above and below the flat structure with no discrete double bonds. The other lone pair of electrons of the oxygen atom extends in the plane of the flat ring system. Note that this implies that oxygen is sp2 hybridized whereas one would normally believe it to be sp3. 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. This allows the extra aromatic stabilization. In chemistry, an aromatic molecule is one in which electrons are free to cycle around circular arrangements of atoms, which are alternately singly and doubly bonded to one another. ... A lone pair is an electron pair without bonding or sharing with other atoms. ... e- redirects here. ... In chemistry, delocalized electrons are electrons in a molecule that do not belong to a single atom or a covalent bond. ... In organic chemistry, Hückels rule estimates whether a planar ring molecule will have aromatic properties. ... Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... four sp³ orbitals three sp² orbitals In chemistry, hybridisation or hybridization (see also spelling differences) is the concept of mixing atomic orbitals to form new hybrid orbitals suitable for the qualitative description of atomic bonding properties. ... Electron configuration is the arrangement of electrons in an atom, molecule or other body. ...

Synthesis

• A classic furan organic synthesis is the Feist-Benary synthesis.
• One of the most simple synthesis methods for furans is the reaction of 1,4-diketones with phosphorus pentoxide (P₂O₅) in the Paal-Knorr Synthesis. It is interesting that the thiophene formation reaction of 1,4-diketones with Lawesson's reagent also forms furans as side products.

Organic synthesis is the construction of organic molecules via chemical processes. ... The Feist-Benary synthesis is an organic reaction between α-halogen ketones and β-dicarbonyl compounds to substituted furan compounds . This condensation reaction is catalyzed by amines such as ammonia and pyridine. ... Ketone group A ketone(key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. ... Phosphorus pentoxide, perhaps more accurately diphosphorus pentoxide, is so called because of its empirical formula P2O5, as should be expected of any element in oxidation number +5. ... The Paal-Knorr synthesis is a reaction where 1,4-diketones are converted to either furans, thiophenes or pyrroles. ... Thiophene is an aromatic heterocyclic compound consisting of four carbon atoms and one sulfur atom in a five-membered ring. ... Lawessons reagent or LR is a chemical compound used in organic synthesis as a thiation agent. ...

Reactions

• Due to its aromaticity, furan's behavior is quite dissimilar to that of the more typical heterocyclic ethers such as tetrahydrofuran. It is considerably more reactive than benzene in electrophilic substitution reactions.
• Furan is a diene in Diels-Alder reactions with electron-deficient dienophiles such as ethyl (E)-3-nitroacrylate.^[1] The reaction product is a mixture of isomers with preference for the endo isomer:

• Furans are hydrogenated to dihydrofurans and tetrahydrofurans.

Ether is the general name for a class of chemical compounds which contain an ether group — an oxygen atom connected to two (substituted) alkyl groups. ... Tetrahydrofuran, also known as THF, hydrofuran, oxolane, oxacyclopentane, or furanidine, is a heterocyclic organic compound. ... Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ... Electrophilic substitution reactions are chemical reactions in which an electrophile displaces another group, typically but not always hydrogen. ... Dienes are hydrocarbons which contain two double bonds. ... The Diels-Alder reaction The Diels-Alder reaction is an organic chemical reaction (specifically, a cycloaddition) between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene system. ... A dienophile can only properly be explained by being familar with a Diels-Alder reaction. ... Endo-exo isomerism is a special type of isomerism found in organic compounds with a substituent on a bridged ring system. ... Image File history File links Size of this preview: 800 × 182 pixelsFull resolution (862 × 196 pixel, file size: 5 KB, MIME type: image/png) Furan cycloaddition I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU... Hydrogenation is a class of chemical reactions which result an addition of hydrogen (H2) usually to unsaturated organic compounds. ... For other uses of THF, see THF (disambiguation) Tetrahydrofuran is a heterocyclic organic compound. ...

See also

• Tetrahydrofuran (THF), the fully hydrogenated analog of furan and a common solvent.
• Pyrrole, the nitrogen analog of furan.
• Thiophene, the sulfur analog of furan.
• Selenophene, the selenium analog of furan.
• Tellurophene, the tellurium analog of furan.
• Benzofuran, furan with a fused benzene ring.
• Dibenzofuran, a compound class similar to dibenzodioxins.
• Simple aromatic rings

Tetrahydrofuran, also known as THF, hydrofuran, oxolane, oxacyclopentane, or furanidine, is a heterocyclic organic compound. ... Hydrogenation is a class of chemical reactions which result an addition of hydrogen (H2) usually to unsaturated organic compounds. ... A solvent is a liquid that dissolves a solid, liquid, or gaseous solute, resulting in a solution. ... Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... Thiophene is an aromatic heterocyclic compound consisting of four carbon atoms and one sulfur atom in a five-membered ring. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Standard atomic weight 32. ... Se redirects here. ... General Name, Symbol, Number tellurium, Te, 52 Chemical series metalloids Group, Period, Block 16, 5, p Appearance silvery lustrous gray Standard atomic weight 127. ... Benzofuran, also known as Cumaron, Coumarone, or benzo[b]furan, is a heterocyclic aromatic organic compound. ... Categories: Chemistry stubs ... Space-filling model of 2,3,7,8- tetrachlorodibenzo-p-dioxin Structure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) Dioxin is the popular name for the family of halogenated organic compounds, the most common consisting of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs). ... Simple aromatic rings are aromatic organic compounds (also known as arenes or aromatics) that consist only of conjugated planar ring systems with delocalized pi electron clouds instead of discrete alternating single and double bonds. ...

External links

• Computational Chemistry Wiki
• Recent synthetic methods
• Links to external chemical sources

References

1. ^ The oxanorbornene approach to 3-hydroxy, 3,4-dihydroxy and 3,4,5-trihydroxy derivatives of 2-aminocyclohexanecarboxylic acid Masesane I, Batsanov A, Howard J, Modal R, Steel P Beilstein Journal of Organic Chemistry, 2006 2:9 Online Article