Synthesis of 1-Acetoxy-1-heptene – DMAP as Catalyst

D.Ladjama, J.J. Riehl, Synthesis, 504 (1979)

 

          

                                                                                (84%)

  1. To  a stirred suspension of potassium hydride (4.4 g, 0.11 mol) in dry 1,2-dimethoxyethane (50 mL), at -5° C under nitrogen, is added heptanal (11.4 g, 0.1 mol) in dry 1,2-dimethoxyethane (10 mL). Hydrogen evolution is quantitative within 10-12 min.
  2. The enolate in solution is added by syringe to a solution of excess acetyl chloride (15.7 g, 0.2 mol), DMAP (0.6 g, 5 mmol), and 1,2-dimethoxyethane (30 mL) and stirred at room temperature for 15 min.
  3. The reaction mixture is slurried into a two-phase ice-water/pentane system. After separation, the organic phase is washed twice with a saturated aqueous sodium hydrogen carbonate solution then with water, and dried with magnesium sulfate.
  4. The solvent is evaporated in vacuum, and the residual product is distilled in vacuo to give a mixture of cis- and trans-1-acetoxy-1-heptene (13.1 g, 84%); b.p. 83-85°/15 torr.

Click on the Keywords below to see other related reactions:

Acylation

Enol

Acetylation