2-Butyne (dimethylacetylene, crotonylene or but-2-yne) is an alkyne with

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

CH₃C≡CCH₃. Produced artificially, it is a colorless, volatile, pungent liquid at standard temperature and pressure. 2-Butyne is of interest to physical chemists because of its very low torsional barrier and the problem of determining that barrier using high-resolution infrared spectroscopy. Analysis of its spectrum leads to a determination that the torsional barrier is only 6 cm⁻¹ (1.2 J or 72 J mol⁻¹). However, it has not been determined whether the equilibrium structure is eclipsed (D_3h) or staggered (D_3d). Symmetry analysis using the Molecular Symmetry Group G₃₆ shows that one would need to analyse its high resolution rotation-vibration Raman spectrum to determine its equilibrium structure. 2-Butyne (''dimethylethyne'') forms with 5-decyne (''dibutylethyne''),

4-octyne 4-Octyne, also known as dipropylethyne, is a type of alkyne with a triple bond at its fourth carbon (the '4-' indicates the location of the triple bond in the chain). Its formula is C8H14. 4-Octyne forms with 5-decyne, 3-hexyne, and 2-butyne a ...

(''dipropylethyne'') and 3-hexyne (''diethylethyne'') a group of symmetric alkynes.

Synthesis

2-Butyne can be synthesized by the rearrangement reaction of

ethylacetylene 1-Butyne is an organic compound with the chemical formula HC2CH2CH3. It is a colorless combustable gas. 1-Butyne participates in reactions typical for terminal alkynes, such as alkyne metathesis, hydrogenation, condensation with formaldehyde. Base ...

in a solution of

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exp ...

Applications

2-Butyne, along with propyne, is used to synthesize

alkylated Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting al ...

hydroquinone Hydroquinone, also known as benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene, having the chemical formula C6H4(OH)2. It has two hydroxyl groups bonded to a benzene ring in a ''para' ...

s in the

total synthesis Total synthesis is the complete chemical synthesis of a complex molecule, often a natural product, from simple, commercially-available precursors. It usually refers to a process not involving the aid of biological processes, which distinguishes i ...

Vitamin E Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vi ...

References

Alkynes {{hydrocarbon-stub

Synthesis

Applications

See also

References