Iodine → 1,4-Pentadien-3-ol, 3-methyl-1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-

HRID 567389

Reaction equation

HRID 567389 reaction equation
[Mg].II.[CH:4](Br)=[CH2:5].[CH3:7][C:8]1[CH2:13][CH2:12][CH2:11][C:10]([CH3:15])([CH3:14])[C:9]=1/[CH:16]=[CH:17]/[C:18]([CH3:20])=[O:19]>O1CCCC1>[CH3:7][C:8]1[CH2:13][CH2:12][CH2:11][C:10]([CH3:14])([CH3:15])[C:9]=1/[CH:16]=[CH:17]/[C:18]([OH:19])([CH:4]=[CH2:5])[CH3:20]

Participants

6

Reactant 4

HCID 807IodineHCID 11641Bromoethene2×HCID 638014I2-IononeHCID 5462224Magnesium

Product 1

HCID 64368461,4-Pentadien-3-ol, 3-methyl-1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-Yield 87.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Conditions

Temperature
-30 °C

Procedure

1.3 mols of magnesium turnings are placed in a 3 L four-necked flask. 100 ml of tetrahydrofuran (THF) and a iodine crystal are added thereto. 50 ml of a 15% vinyl bromide solution in tetrahydrofuran are added with stirring and under nitrogen atmosphere. The solution immediately decolourizes, while the Grignard starts to form with an exothermic reaction: the mixture is cooled to −30° C. and one mol of beta-ionone dissolved in 500 ml of THF and 950 mL of the above 15% vinyl bromide solution are added at the same time through two dropping tunnels, at such a rate that temperature remains below −15 20° C. After completion of the addition, the cooling bath is removed and the reaction mixture is brought to room temperature. After 2 hours the reaction mixture is poured into 2 ml of ice-water containing 10 g of ammonium chloride under stirring, then is extracted with 700 ml of ethyl acetate. The organic phase is washed twice with 100 ml of 15% sodium chloride aqueous solution and dried over sodium sulfate. Solvent is evaporated off under reduced pressure and the resulting thick oil is distilled under vacuum, collecting 202 g of distillate, consisting of vinyl beta-ionol of purity higher than 95%, as determined by NMR analysis (yield: 87.5%).

Workup

  1. customto form with an exothermic reaction
  2. customremains below −15 20° C
  3. additionAfter completion of the addition
  4. customthe cooling bath is removed
  5. customis brought to room temperature
  6. additionAfter 2 hours the reaction mixture is poured into 2 ml of ice-water containing 10 g of ammonium chloride
  7. stirringunder stirring
  8. extractionis extracted with 700 ml of ethyl acetate
  9. washThe organic phase is washed twice with 100 ml of 15% sodium chloride aqueous solution
  10. dry with materialdried over sodium sulfate
  11. customSolvent is evaporated off under reduced pressure
  12. distillationthe resulting thick oil is distilled under vacuum
  13. distillationcollecting 202 g of distillate

Sources & evidence

ORD record
ord-96806ee6beac47ce8803dbe209115dcc
Source dataset
uspto-grants-2001_01
Patent number
US06177579B1

Linked notes

Loading…