Acetic Anhydride → 1-Acetoxy-2-(6-carbethoxyhexyl)cyclopent-1-ene

HRID 1605755Notes

Reaction equation

HRID 1605755 reaction equation
[C:1]([CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH:12]1[CH2:16][CH2:15][CH2:14][C:13]1=[O:17])([O:3][CH2:4][CH3:5])=[O:2].[C:18](OC(=O)C)(=[O:20])[CH3:19].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C(O)(=O)C>[C:18]([O:17][C:13]1[CH2:14][CH2:15][CH2:16][C:12]=1[CH2:11][CH2:10][CH2:9][CH2:8][CH2:7][CH2:6][C:1]([O:3][CH2:4][CH3:5])=[O:2])(=[O:20])[CH3:19]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 521998p-Toluenesulfonic acid monohydrateHCID 558615Ethyl 7-(2-oxocyclopentyl)heptanoate

Product 1

HCID 132897851-Acetoxy-2-(6-carbethoxyhexyl)cyclopent-1-ene

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A stirred solution of 100 g. of 2-(6-carbethoxyhexyl)-cyclopentan-1-one (Example 9) in 250 ml. of acetic anhydride containing 0.940 g. of p-toluenesulfonic acid monohydrate is heated to boiling under partial reflux allowing distillate at 118°C. or less (i.e., acetic acid) to escape through a Vigreaux column equipped with a condenser to collect the distillate. After 16 hours, during which period acetic anhydride is added in portions in order to keep the solvent level at at least 100 ml., the solution is cooled and poured cautiously into a stirred cold mixture of saturated sodium bicarbonate solution (400 ml.) and hexane (250 ml.). The resulting mixture is stirred for an additional 30 minutes during which period solid sodium bicarbonate is added periodically to insure a basic solution. The hexane layer is separated and washed with saturated sodium chloride solution, dried with anhydrous magnesium sulfate and taken to dryness. Distillation of the residual oil gives 102 g. (87%) of pale yellow oil, b.p. 118°C. (0.07 mm).

Workup

  1. temperatureunder partial reflux
  2. customallowing distillate at 118°C. or less
  3. customequipped with a condenser
  4. distillationto collect the distillate
  5. additionduring which period acetic anhydride is added in portions in order
  6. temperature, the solution is cooled
  7. additionpoured cautiously into a stirred cold mixture of saturated sodium bicarbonate solution (400 ml.) and hexane (250 ml.)
  8. additionis added periodically
  9. customThe hexane layer is separated
  10. washwashed with saturated sodium chloride solution
  11. dry with materialdried with anhydrous magnesium sulfate
  12. distillationDistillation of the residual oil
  13. customgives 102 g

Sources & evidence

ORD record
ord-81aa913204f04d65bd6b137d8da85e52
Source dataset
uspto-grants-1976_04
Patent number
US03950406

Reaction notes

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