organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...

, an alkynol (shortened to ynol) is an alkyne with a hydroxyl group affixed to one of the two

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...

atoms composing the

triple bond A triple bond in chemistry is a chemical bond between two atoms involving six bonding electrons instead of the usual two in a covalent single bond. Triple bonds are stronger than the equivalent single bonds or double bonds, with a bond order o ...

(). The

deprotonated Deprotonation (or dehydronation) is the removal (transfer) of a proton (or hydron, or hydrogen cation), (H+) from a Brønsted–Lowry acid in an acid–base reaction.Henry Jakubowski, Biochemistry Online Chapter 2A3, https://employees.csbsju.ed ...

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

s of ynols are known as ''

ynolate Ynolates are chemical compounds with a negatively charged oxygen attached to an alkyne functionality. They were first synthesized in 1975 by Schöllkopf and Hoppe via the ''n''-butyllithium fragmentation of 3,4-diphenylisoxazole. Synthetically, ...

s''. An ynol with hydroxyl groups on both sides of its triple bond is known as an ynediol; only one ynediol,

acetylenediol Acetylenediol, or ethynediol, is a chemical substance with formula HO−C≡C−OH (an ynol). It is the diol of acetylene. Acetylenediol is unstable in the condensed phase, although its tautomer glyoxal (CHO)2 is well known. Detection Acetyl ...

, exists.

Ynolates

Ynolates are chemical compounds with a negatively charged oxygen atom attached to an alkyne functionality. They were first synthesized in 1975 by Schöllkopf and Hoppe via the ''n''-butyllithium fragmentation of 3,4-diphenylisoxazole. Synthetically, they behave as

ketene In organic chemistry, a ketene is an organic compound of the form , where R and R' are two arbitrary monovalent chemical groups (or two separate substitution sites in the same molecule). The name may also refer to the specific compound ethen ...

precursors or

synthon In retrosynthetic analysis, a synthon is a hypothetical unit within a target molecule that represents a potential starting reagent in the retroactive synthesis of that target molecule. The term was coined in 1967 by E. J. Corey. He noted in 1 ...

Ynol–ketene tautomerism

Ynols can interconvert with

s, much like

enol In organic chemistry, alkenols (shortened to enols) are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene ( olefin) with a hydroxyl group attached to one end of the alkene double bond (). The t ...

s can with

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl grou ...

s and

ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bo ...

s. The ynol

tautomer Tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hydr ...

is usually unstable, does not survive long, and changes into the ketene. This is because

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

is more

electronegative Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the d ...

than

and thus forms stronger bonds. For instance,

ethynol Ethynol (or hydroxyacetylene) is an alkyne–alcohol ( ynol) with the formula C2H2O. It is the much-less-stable tautomer of ethenone. At low temperature in a solid argon matrix it is possible to tautomerise ethenone to form ethynol. See also * ...

quickly interconverts with

ethenone In organic chemistry, ethenone is the formal name for ketene, an organic compound with formula or . It is the simplest member of the ketene class. It is an important reagent for acetylations. Properties Ethenone is a highly reactive gas (a ...

: {, class="wikitable" style="margin: 1em auto 1em auto" ! colspan="2" , Ynol-ketene tautomers , - style="background-color:#ffffff;" , Ethynol-3D-vdW

, ,

, - align="center" ,

Ethynol Ethynol (or hydroxyacetylene) is an alkyne–alcohol ( ynol) with the formula C2H2O. It is the much-less-stable tautomer of ethenone. At low temperature in a solid argon matrix it is possible to tautomerise ethenone to form ethynol. See also * ...

, ,

Ethenone In organic chemistry, ethenone is the formal name for ketene, an organic compound with formula or . It is the simplest member of the ketene class. It is an important reagent for acetylations. Properties Ethenone is a highly reactive gas (a ...

Ynolates

Ynol–ketene tautomerism

See also

References