Cyclohexanone → 1-Oxaspiro[5.5]undec-3-ene, 4-methyl-

HRID 716487Notes

Reaction equation

HRID 716487 reaction equation
[C:1]1(=[O:7])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[CH3:8][C:9]([CH2:11][CH2:12]O)=[CH2:10]>CC1C=CC(S(O)(=O)=O)=CC=1.C1(C)C=CC=CC=1>[CH3:8][C:9]1[CH2:10][C:1]2([CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]2)[O:7][CH2:12][CH:11]=1

Participants

5

Reactant 2

HCID 7967CyclohexanoneHCID 129883-Methyl-3-buten-1-ol

Product 1

HCID 111164241-Oxaspiro[5.5]undec-3-ene, 4-methyl-Yield 80%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 1140TolueneSolvent

Conditions

Temperature
115 °C

Procedure

A mixture of p-TSA (20 g, 0.105 mol) and toluene (2 L) was heated to 115° C. To this mixture were added cyclohexanone (980 g, 10 mols) and isoprenol (946 g, 11 mols) and heated further for 3-6 h. Water was removed from the reaction azeotropically. The reaction mixture was then cooled to room temperature. The organic phase was washed with a 5% Na2CO3 solution, washed with water dried and concentrated and distilled further to provide 4-methyl-1-oxaspiro [5.5] undec-3-ene (1.32 kg) having a purity of 98% (sum of the isomers) for a total yield of 80%.

Workup

  1. temperatureheated further for 3-6 h
  2. customWater was removed from the reaction azeotropically
  3. temperatureThe reaction mixture was then cooled to room temperature
  4. washThe organic phase was washed with a 5% Na2CO3 solution
  5. washwashed with water
  6. customdried
  7. concentrationconcentrated
  8. distillationdistilled further

Sources & evidence

ORD record
ord-164427831c5d4e9e8728c6430438f806
Source dataset
uspto-grants-2015_11
Patent number
US09187709B2

Reaction notes

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