2,2,4,4-Tetramethylcyclobutanedione
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Preferred IUPAC name 2,2,4,4-Tetramethylcyclobutane-1,3-dione | |
Other names Tetramethyl-1,3-cyclobutanedione, Tetramethylcyclobuta-1,3-dione | |
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ECHA InfoCard | 100.012.063 ![]() |
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Properties | |
Chemical formula | C8H12O2 |
Molar mass | 140.182 g·mol−1 |
Appearance | Colorless or white solid |
Melting point | 112–115 °C (234–239 °F; 385–388 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references |
2,2,4,4-Tetramethylcyclobutanedione is the organic compound with the formula (CH3)4C4O2. The compound is a diketone of cyclobutane, bearing four methyl groups. It is a white solid that is used as a precursor to diverse industrial products.
Synthesis and reactions
2,2,4,4-Tetramethylcyclobutanedione is the head-to-tail dimer of dimethylketene. It arises spontaneously when dimethylketene is produced by dehydrohalogenation of isobutyryl chloride with triethylamine.[1]
In the presence of aluminium trichloride, 2,2,4,4-tetramethylcyclobutanedione isomerizes to the lactone dimethylketene dimer (4-isopropylidene-3,3-dimethyl-2-oxetanone).[2] Dimethylketene dimer is a precursor to various alkyl ketene dimers, which are used in papermaking.
![Isomerisierung von Tetramethyl-1,3-cyclobutandion zum Dimethylketendimer Isomerisation of tetramethyl-1,3-cyclobutanedione to Dimethyl ketene dimer](http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Isomerisierung_von_Tetramethyl-1%2C3-cyclobutandion.svg/350px-Isomerisierung_von_Tetramethyl-1%2C3-cyclobutandion.svg.png)
Hydrogenation of 2,2,4,4-tetramethylcyclobutanedione gives 2,2,4,4-tetramethylcyclobutanediol, which is of interest in polymer chemistry.
References
- ^ R. Huisgen, P. Otto (1968), "The mechanism of dimerization of dimethylketene", J. Am. Chem. Soc., vol. 90, no. 19, pp. 5342–5343, doi:10.1021/ja01021a090
- ^ R.H. Hasek; R.D. Clark; G.L. Mayberry (1968). "Dimethylketene β-Lactone Dimer". Organic Syntheses. 48: 72. doi:10.15227/orgsyn.048.0072.