Oxetan-2-ones

Oxetan-2-ones
Oxetan-2-one (general formula) (β-lactone)
Oxetan-2-one
Diketen

Oxetan-2-ones are cyclic esters ( lactones ) which are derived from β- hydroxycarboxylic acids. The unsubstituted parent of this group of substances is oxetan-2-one (propiolactone) with the empirical formula C ₃ H ₄ O ₂ .

Oxetan-2-ones can also be classified as α-oxo derivatives of the group of oxetanes . The most important industrial oxetan-2-one is diketene .

Manufacturing

Oxetan-2-ones have the basic structure of β-lactones . They can be made by various methods:

Elimination of water from β-hydroxycarboxylic acids under the action of phenylsulfonyl chloride (PhSO ₂ Cl) in pyridine.

The reaction of ketenes with aldehydes in the presence of Lewis acid (z. B. BF ₃ or ZnCl ₂ ) gives the correspondingly substituted oxetan-2-one, z. B.

Diketene is formed by the dimerization of ketene :

An alkylated ketene can be produced from fatty acids via the carboxylic acid chloride , which quickly cyclizes to a dialkylated ketene dimer. These ketene waxes are used to make paper water repellent ( sizing ).

Reactivity

The reaction of diketene 1 with ethanol produces ethyl acetoacetate 2 :

Diketene reacts analogously with substituted aromatic amines to form acetoacetanilides (arylides), which are precursors for mostly yellow, orange or red azo dyes and azo pigments .

The industrial synthesis of the sweetener acesulfame -K is based on the conversion of diketene with amidosulfonic acid and cyclization using SO ₃ .

Individual evidence

↑ ^a ^b ^c ^d Theophil Eicher , Siegfried Hauptmann , Andreas Speicher: The Chemistry of Heterocycles , Wiley-VCH, 2012, ISBN 978-3-527-32747-8 , pp. 47-48
↑ Patent US5344943A : Long-chain ketene dimers. Applied December 30, 1991 , published December 29, 1992 , applicant: Akzo Nobel NV, inventor: Nils Brolund. ‌
↑ Patent EP0218076B1 : Process for the production of the non-toxic salts of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide. Filed on Aug. 27, 1986 , published on January 3, 1990 , Applicant: Hoechst , inventors Dieter Reusch Ling, Adolf Linkies et al ..

[Eicher1-1] Theophil Eicher , Siegfried Hauptmann , Andreas Speicher: The Chemistry of Heterocycles , Wiley-VCH, 2012, ISBN 978-3-527-32747-8 , pp. 47-48

[2] Patent US5344943A : Long-chain ketene dimers. Applied December 30, 1991 , published December 29, 1992 , applicant: Akzo Nobel NV, inventor: Nils Brolund. ‌

[3] Patent EP0218076B1 : Process for the production of the non-toxic salts of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide. Filed on Aug. 27, 1986 , published on January 3, 1990 , Applicant: Hoechst , inventors Dieter Reusch Ling, Adolf Linkies et al ..