A Publication
of Reliable Methods
for the Preparation
of Organic Compounds
Annual Volume
Org. Synth. 1949, 29, 1
DOI: 10.15227/orgsyn.029.0001
[Ketone, 1-cyclohexenyl methyl]
Submitted by J. H. Saunders1
Checked by E. L. Jenner and R. S. Schreiber.
1. Procedure
In a 500-ml. round-bottomed flask are placed 40 g. (0.32 mole) of 1-ethynylcyclohexanol (p. 416), 250 ml. of dry benzene, 10 g. of phosphorus pentoxide, and a boiling chip. A reflux condenser is attached to the flask, and the benzene solution is refluxed gently on a steam cone for 2.5 hours. At the end of that time the contents of the flask are cooled and the benzene is decanted from the phosphorus pentoxide, washed once with 100 ml. of 5% sodium bicarbonate solution, and dried over 15 g. of anhydrous sodium sulfate. The benzene is removed by distillation at atmospheric pressure, and the acetylcyclohexene is carefully fractionated at reduced pressure, through a 15-cm. helix-packed column. The yield of material boiling at 85–88°/22 mm., nD20 1.4892, is 22.5–28 g. (56–70%).
3. Discussion
1-Acetylcyclohexene has been prepared by treating cyclohexene with acetyl chloride and aluminum chloride,2,3,4,5 by treating 1-ethynylcyclohexanol with oxalic acid6 or 85% aqueous formic acid,5,7,8,9 and by the dehydrohalogenation and hydrolysis of ethylidenecyclohexane nitrosochloride.10 1-Acetylcyclohexene and its homologs also have been prepared by the addition of a suitable diene to vinylacetylene in the presence of water and a mercury salt.11

References and Notes
  1. This investigation was carried out under the sponsorship of the Office of Rubber Reserve, Reconstruction Finance Corporation, in connection with the Government Synthetic Rubber Program.
  2. Darzens, Compt. rend., 150, 707 (1910).
  3. Christ and Fuson, J. Am. Chem. Soc., 59, 895 (1937).
  4. Nightingale, Milberger, and Tomisek, J. Org. Chem., 13, 358 (1948).
  5. Hurd and Christ, J. Am. Chem. Soc., 59, 120 (1937).
  6. Levina and Vinogradova, J. Applied Chem. U.S.S.R., 9, 1299 (1936) [C. A., 31, 2587 (1937)].
  7. Rupe, Messner, and Kambli, Helv. Chim. Acta, 11, 454 (1928).
  8. Fischer and Löwenberg, Ann., 475, 203 (1929).
  9. Chanley, J. Am. Chem. Soc., 70, 246 (1948).
  10. Wallach, Ann., 360, 46 (1908).
  11. U. S. pat. 2,301,515 [C. A., 37, 2015 (1943)].

Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

ethylidenecyclohexane nitrosochloride

Benzene (71-43-2)

acetyl chloride (75-36-5)

sodium bicarbonate (144-55-8)

Cyclohexene (110-83-8)

sodium sulfate (7757-82-6)

formic acid (64-18-6)

Oxalic acid (144-62-7)

mercury (7439-97-6)

aluminum chloride (3495-54-3)

Ketone, 1-cyclohexenyl methyl,
acetylcyclohexene (932-66-1)

1-Ethynylcyclohexanol (78-27-3)

vinylacetylene (689-97-4)

phosphorus pentoxide (1314-56-3)