p-Toluenesulfonic acid → 1-Oxaspiro[5.5]undec-3-ene, 4-methyl-

HRID 716483Notes

Reaction equation

HRID 716483 reaction equation
[CH3:1][C:2]1[CH:3]=[CH:4][C:5](S(O)(=O)=O)=[CH:6][CH:7]=1.[C:12]1(=[O:18])CC[CH2:15][CH2:14][CH2:13]1.CC(CCO)=C>C1(C)C=CC=CC=1>[CH3:15][C:14]1[CH2:1][C:2]2([CH2:3][CH2:4][CH2:5][CH2:6][CH2:7]2)[O:18][CH2:12][CH:13]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 7967CyclohexanoneHCID 129883-Methyl-3-buten-1-ol

Product 1

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

Reagents, catalysts & solvents 1

HCID 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 provideto 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-10c96fbd49ab488cae3b15dabd957887
Source dataset
uspto-grants-2015_11
Patent number
US09187709B2

Reaction notes

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