Org. Synth. 1958, 38, 25
DOI: 10.15227/orgsyn.038.0025
5,5-DIMETHYL-2-n-PENTYLTETRAHYDROFURAN
[Furan, tetrahydro-2,2-dimethyl-5-pentyl-]
Submitted by J. Colonge and R. Marey
1.
Checked by V. Boekelheide and H. Kaempfen.
1. Procedure
In a
100-ml., three-necked, round-bottomed flask, fitted with a sealed
mechanical stirrer, a
reflux condenser, and a
thermometer reaching to the bottom of the flask, are placed
37.6 g. (0.2 mole) of 2-methyl-2,5-decanediol (p.601) and
17 g. of 85% phosphoric acid. The limpid liquid obtained is heated and maintained at 125° for 40 minutes. Then the acidic lower layer is discarded, and the organic layer is washed with three or four 50-ml. portions of lukewarm distilled water.
Distillation of the resulting crude oil using a simple fractionating column gives 32–33 g. (94–97%) of pure 5,5-dimethyl-2-n-pentyltetrahydrofuran as a colorless liquid boiling at 31–33°/1.5 mm.; nD25 1.4257 (Note 1).
2. Notes
1.
The submitters have also prepared
5,5-dimethyl-2-heptyltetrahydrofuran,
nD25 1.4360, by a similar dehydration of
2-methyl-2,5-undecanediol obtained from the reaction of
methylmagnesium bromide and
γ-undecanoic acid lactone.
3. Discussion
There is no report on the preparation of 5,5-dimethyl-2-n-pentyltetrahydrofuran.
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
phosphoric acid (7664-38-2)
methylmagnesium bromide (75-16-1)
Furan, tetrahydro-2,2-dimethyl-5-pentyl-,
5,5-DIMETHYL-2-n-PENTYLTETRAHYDROFURAN (53684-53-0)
2-Methyl-2,5-decanediol (53731-34-3)
5,5-dimethyl-2-heptyltetrahydrofuran
2-methyl-2,5-undecanediol
γ-undecanoic acid lactone (104-67-6)
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