p-Toluenesulfonic acid → 2,2,4,5-tetramethyl-4-hexen-3-one

HRID 440637Notes

Reaction equation

HRID 440637 reaction equation
[CH3:1][C:2]([CH3:11])([C:4](=[O:10])[CH:5]([CH3:9])[C:6]([CH3:8])=[CH2:7])[CH3:3].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:3][C:2]([CH3:11])([C:4](=[O:10])[C:5]([CH3:9])=[C:6]([CH3:8])[CH3:7])[CH3:1]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 118159642,2,4,5-Tetramethyl-5-hexen-3-one

Product 1

HCID 112521302,2,4,5-tetramethyl-4-hexen-3-one

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

30.8 g (0.2 mole) of 2,2,4,5-tetramethyl-5-hexen-3-one were heated to 100° in 100 ml of toluene in the presence of 3.08 g of p-toluenesulfonic acid. After 24 h, the mixture was cooled down and extracted with ether. After neutralizing with an aqueous solution saturated with NaHCO3, the organic phase was washed with water, then with a solution saturated with NaCl, and dried with Na2SO4. Evaporation and distillation of the residue, followed by fractional distillation, provided a fraction having B.p. 60°/1.06×103Pa NMR(1H, 360MHz): 1.18(s, 9H); 1.57(s, 3H); 1.66(s, 3H); 1.77(s, 3H) δppm MS:m/z:154(3, M+), 97(100), 69(62), 41(65), 39(20).

Workup

  1. temperaturethe mixture was cooled down
  2. extractionextracted with ether
  3. washthe organic phase was washed with water
  4. dry with materialwith a solution saturated with NaCl, and dried with Na2SO4
  5. customEvaporation and distillation of the residue
  6. distillationfollowed by fractional distillation
  7. customprovided a fraction

Sources & evidence

ORD record
ord-fedafcc0e7064269a05f2f541a971f1c
Source dataset
uspto-grants-1996_05
Patent number
US05521151

Reaction notes

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