p-Toluenesulfonic acid → 3-Cyclopentene-1-acetic acid, 2,2,3-trimethyl-, ethyl ester

HRID 280797Notes

Reaction equation

HRID 280797 reaction equation
[CH3:1][C:2]1([CH3:12])[C:6]([CH3:7])=[CH:5][CH2:4][CH:3]1[CH2:8][C:9]([OH:11])=[O:10].[C:13]1(C)C=CC(S(O)(=O)=O)=C[CH:14]=1>C(O)C>[CH2:13]([O:10][C:9](=[O:11])[CH2:8][CH:3]1[CH2:4][CH:5]=[C:6]([CH3:7])[C:2]1([CH3:12])[CH3:1])[CH3:14]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 117235(2,2,3-Trimethylcyclopent-3-en-1-yl)acetic acid

Product 1

HCID 211561413-Cyclopentene-1-acetic acid, 2,2,3-trimethyl-, ethyl esterYield 3,289.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
78 °C

Procedure

A solution of α-campholenic acid (100 g) and p-toluene-sulfonic acid (2 g) in ethanol (3 liters) was kept at reflux (78° C.) for 3 hours. The alcohol was then removed, the residue taken up in CH2Cl2 (1.5 liters) and the solution extracted with ice cold 5% aqueous sodium hydroxide (2×500 ml) and water (500 ml). Concentration of the CH2Cl2 solution gave a crude product (81 g) which was distilled through a 9" glass packed column to give 75 g of a colorless liquid; bp 90° C. @ 4,8 mm Hg; analysis: 97% (CW 20M fused silica column, 120° C.) ethyl α-campholenate.

Workup

  1. customThe alcohol was then removed
  2. extractionthe solution extracted with ice cold 5% aqueous sodium hydroxide (2×500 ml) and water (500 ml)
  3. customConcentration of the CH2Cl2 solution gave a crude product (81 g) which
  4. distillationwas distilled through a 9" glass

Sources & evidence

ORD record
ord-b7f76c187f79474e8f2b4a0a52d19eb8
Source dataset
uspto-grants-1986_05
Patent number
US04590953

Reaction notes

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