Boron trifluoride etherate → 2-Methoxy-2,6,6-trimethyl-9-methylidenebicyclo[3.3.1]nonane

HRID 1493558Notes

Reaction equation

HRID 1493558 reaction equation
[CH3:1][C:2]1[CH:7]([CH2:8][CH2:9][C:10]([CH3:12])=[O:11])[C:6]([CH3:14])([CH3:13])[CH2:5][CH2:4][CH:3]=1.[CH:15](OC)(OC)OC.B(F)(F)F.CCOCC.[OH-].[K+]>C(Cl)Cl>[CH3:15][O:11][C:10]1([CH3:12])[CH2:9][CH2:8][CH:7]2[C:2](=[CH2:1])[CH:3]1[CH2:4][CH2:5][C:6]2([CH3:14])[CH3:13]

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 9005Trimethyl orthoformateHCID 14797Potassium HydroxideHCID 35821Dihydro-alpha-ionone

Product 1

HCID 197807772-Methoxy-2,6,6-trimethyl-9-methylidenebicyclo[3.3.1]nonaneYield 87%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

120 g (0.563 mol) of dihydro-α-ionone, 65 g (0.612 mol) of trimethyl orthoformate and 200 ml of methylene chloride are treated dropwise while stirring during 15 minutes with a solution of 8 g of boron trifluoride etherate in 60 ml of methylene chloride and the mixture is subsequently held under reflux for 105 minutes. The reaction mixture is cooled and poured into 500 ml of a 5% aqueous potassium hydroxide solution. After the addition of 500 ml of methylene chloride and vigorous intermixing the phases are separated, the organic phase is washed with water and the solvent is distilled off. The residue (197.1 g) is fractionated in a vacuum over a 15 cm Widmer column. There are obtained 100.2 g of product of b.p. 44°-47°/0.06-0.07 mbar (yield 87% of theory based on pure dihydro-α-ionone) as a colorless liquid which contains 72.3% of exo isomer and 20.1% of endo isomer of the desired bicyclo-nonane.

Workup

  1. temperatureunder reflux for 105 minutes
  2. temperatureThe reaction mixture is cooled
  3. customare separated
  4. washthe organic phase is washed with water
  5. distillationthe solvent is distilled off

Sources & evidence

ORD record
ord-fa3391ea36f143bdb0f97d306c0eac75
Source dataset
uspto-grants-1991_06
Patent number
US05023232

Reaction notes

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