The IUPAC (International Union of Pure and Applied Chemistry) name for furan can be 1,4-Epoxybuta-1,3-diene or 1-Oxacyclopenta-2,4-diene. These names systematically describe the chemical structure of this important heterocyclic compound.
Furan is a five-membered aromatic ring containing one oxygen atom and two double bonds. It is a fundamental building block in organic chemistry and is found in various natural products.
Detailed IUPAC Naming
IUPAC nomenclature provides standardized methods for naming chemical compounds. Furan, being a heterocyclic compound, can be named using different systematic approaches:
- Replacement Nomenclature (Oxacyclopentadiene): This method views the oxygen atom as replacing a carbon atom in the corresponding carbocyclic ring. Since it's a five-membered ring with two double bonds, the parent hydrocarbon would be cyclopentadiene. Replacing a carbon with oxygen leads to 1-Oxacyclopenta-2,4-diene. The '1' indicates the position of the oxygen, and '2,4' indicate the positions of the double bonds relative to the oxygen.
- Fusion/Bridge Nomenclature (Epoxybuta-1,3-diene): This method describes furan as a buta-1,3-diene unit where positions 1 and 4 are bridged by an oxygen atom. This gives the name 1,4-Epoxybuta-1,3-diene.
Both names are considered systematic and chemically accurate according to IUPAC rules, reflecting different ways of describing the same molecular structure.
Common and Other Names for Furan
While the IUPAC names are systematic, furan itself is a highly recognized and accepted common name, often preferred in general chemical discourse due to its simplicity. Other names are also used, though less frequently as systematic IUPAC names:
| Category | Name(s) |
|---|---|
| Systematic IUPAC | 1,4-Epoxybuta-1,3-diene, 1-Oxacyclopenta-2,4-diene |
| Other Names | Oxole, Oxa[5]annulene, 1,4-Epoxy-1,3-butadiene, 5-Oxacyclopenta-1,3-diene, 5-Oxacyclo-1,3-pentadiene, Furfuran, Divinylene oxide |
Key Properties of Furan
- Chemical Formula: C₄H₄O
- CAS Number: 110-00-9
- Appearance: Colorless, highly flammable liquid.
- Aromaticity: Furan exhibits aromatic properties due to its cyclic, planar structure with six π-electrons (four from the two double bonds and two from the oxygen's lone pair), conforming to Hückel's rule.
- Applications: Furan and its derivatives are used in the synthesis of pharmaceuticals, agrochemicals, and other fine chemicals. It serves as a precursor for the production of tetrahydrofuran (THF), a common solvent.
For more information, you can refer to the Furan Wikipedia page.
