Ethylene Glycol → 2-methyl-2-[p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)propenyl]-phenyl]-1,3-dioxolane

HRID 2286101Notes

Reaction equation

HRID 2286101 reaction equation
[CH3:1][C:2]1([CH3:26])[CH2:11][CH2:10][C:9]([CH3:13])([CH3:12])[C:8]2[CH:7]=[C:6](/[C:14](/[CH3:25])=[CH:15]/[C:16]3[CH:21]=[CH:20][C:19]([C:22](=[O:24])[CH3:23])=[CH:18][CH:17]=3)[CH:5]=[CH:4][C:3]1=2.C1(C)C=CC(S(O)(=O)=O)=CC=1.[CH2:38](O)[CH2:39][OH:40].O>C1C=CC=CC=1>[CH3:23][C:22]1([C:19]2[CH:20]=[CH:21][C:16](/[CH:15]=[C:14](/[C:6]3[CH:5]=[CH:4][C:3]4[C:2]([CH3:26])([CH3:1])[CH2:11][CH2:10][C:9]([CH3:12])([CH3:13])[C:8]=4[CH:7]=3)\[CH3:25])=[CH:17][CH:18]=2)[O:40][CH2:39][CH2:38][O:24]1

Participants

6

Reactant 4

HCID 174Ethylene GlycolHCID 962WaterHCID 6101p-Toluenesulfonic acidHCID 701265334'-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)propenyl]-acetophenone

Product 1

HCID 705400732-methyl-2-[p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)propenyl]-phenyl]-1,3-dioxolane

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

3.0 g of 4'-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)propenyl]-acetophenone (prepared as described in Example 22) dissolved in 40 ml of benzene are treated with a catalytic amount of p-toluenesulphonic acid and 0.6 g of ethyleneglycol and warmed in a Dean-Stark apparatus, the water formed being concurrently separated off. After heating under reflux for 2 days, the mixture is cooled down, introduced into ice/saturated sodium bicarbonate solution and exhaustively extracted with ether. The ether extract is washed twice with a saturated sodium chloride solution, dried over sodium sulphate and evaporated under reduced pressure to remove the solvent. The oily residue is purified by adsorption on silica gel using hexane/ether (9:1) for the elution. The 2-methyl-2-[p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)propenyl]-phenyl]-1,3-dioxolane obtained from the eluate melts at 122°-123° C. after recrystallisation from ether.

Workup

  1. temperaturewarmed in a Dean-Stark apparatus
  2. custombeing concurrently separated off
  3. temperatureAfter heating
  4. temperatureunder reflux for 2 days
  5. temperaturethe mixture is cooled down
  6. additionintroduced into ice/saturated sodium bicarbonate solution
  7. extractionexhaustively extracted with ether
  8. extractionThe ether extract
  9. washis washed twice with a saturated sodium chloride solution
  10. dry with materialdried over sodium sulphate
  11. customevaporated under reduced pressure
  12. customto remove the solvent
  13. customThe oily residue is purified by adsorption on silica gel
  14. washfor the elution

Sources & evidence

ORD record
ord-33aee056a1bf4523b679b041f733ed4a
Source dataset
uspto-grants-1982_04
Patent number
US04326055

Reaction notes

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