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.
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.