Organic Syntheses, CV 5, 1024
[3(2)-Furanone, 4,5-dihydro-2,2,5,5-tetramethyl-]
Submitted by Melvin S. Newman and Walter R. Reichle
1.
Checked by Virgil Boekelheide and Graham Solomons.
1. Procedure
To the solution formed by dissolving
3 g. of mercuric oxide and
10 ml. of concentrated sulfuric acid (Note
1) in 1 l. of water is added
250 g. (1.76 moles) of 2,5-dimethyl-3-hexyne-2,5-diol (Note
2). The mixture is warmed with gentle swirling to dissolve the diol. At 80–90° the clear solution suddenly turns cloudy and the
flask is immersed in a bath of water at about 20°. A colorless oil rises to the surface within a few minutes (Note
3).
The flask is then fitted for steam distillation, and 700–800 ml. of distillate is collected. After addition of
55 g. of sodium chloride to the distillate, the phases are separated in a
1-l. separatory funnel. The organic layer is dried by intermittent stirring with
25 g. of anhydrous magnesium sulfate for 6–10 hours.
The material is filtered and the residual solid washed twice with
50-ml. portions of low-boiling petroleum ether. The combined filtrates are concentrated and distilled through a short packed column to yield
190–205 g. (
76–82%) of
2,2,5,5-tetramethyltetrahydro-3-ketofuran; b.p.
149–151°,
nD25 1.4180.
2. Notes
1. Any other water-soluble mercury salt may be used.
2. Supplied by Air Reduction Chemical Company, 150 East 42nd Street, New York, N. Y.
3. The reaction is fairly exothermic. Cooling is advisable. An increase in acid and mercuric ion concentrations results in a faster reaction starting at a lower temperature.
3. Discussion
The procedure described is essentially that of Richet
2 which has been repeated.
3,4 The reaction is of interest since it provides a facile method of preparing tetrahydro-3-furanones which are useful reagents for alkylation in the Friedel-Crafts reaction.
4
Appendix
Compounds Referenced (Chemical Abstracts Registry Number)
petroleum ether
3(2)-Furanone, 4,5-dihydro-2,2,5,5-tetramethyl-
sulfuric acid (7664-93-9)
sodium chloride (7647-14-5)
mercuric oxide (21908-53-2)
magnesium sulfate (7487-88-9)
2,2,5,5-Tetramethyltetrahydro-3-ketofuran (5455-94-7)
2,5-dimethyl-3-hexyne-2,5-diol (142-30-3)
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