Reaction #64853

Reaction equation

potassium dihydrogen phosphate

dihydro-α-ionone

sodium hypochlorite

acetic acid

→

4-(3-chloro-2-methylidene-6,6-dimethyl-cyclohex-1-yl)-butan-2-one

Solvents

water

methylene chloride

Conditions

Workup

1. 1
   Otherfitted with a stirrer
2. 2
   Otherthermometer, condenser and dropping
3. 3
   workup.ADDITIONwas added
4. 4
   Temperaturethe resulting emulsion was cooled in an ice bath
5. 5
   workup.ADDITIONa further 350 ml (0.5 mol) was added
6. 6
   OtherAfter a total reaction time of 27 hours the phases were separated
7. 7
   Extractionthe aqueous phase was extracted 4 times with methylene chloride
8. 8
   WashThe combined organic phases were washed neutral once with water, twice with saturated NaHCO3 solution
9. 9
   Dryinga further 3 times with water, dried over MgSO4
10. 10
    Filtrationfiltered
11. 11
    Otherevaporated (bath temperature=room temperature)

Procedure

388 g (2 mol) of dihydro-α-ionone was placed in 2.2 l of methylene chloride in a 10 l four-necked flask fitted with a stirrer, thermometer, condenser and dropping funnel. Then, 660 g (4.6 mol) of potassium dihydrogen phosphate dissolved in 3 l of water was added and the resulting emulsion was cooled in an ice bath. 1.6 (2.3 mol) of sodium hypochlorite solution (~12%) was added at about 10° within 1.5 hours and, after about 3 hours at 15°, a further 350 ml (0.5 mol) was added. The pH value of the mixture was adjusted to ~5.5 with acetic acid and it was stirred at room temperature. After a total reaction time of 27 hours the phases were separated and the aqueous phase was extracted 4 times with methylene chloride. The combined organic phases were washed neutral once with water, twice with saturated NaHCO3 solution and a further 3 times with water, dried over MgSO4, filtered and evaporated (bath temperature=room temperature). 407.45 g 4-(3-chloro-2-methylidene-6,6-dimethyl-cyclohex-1-yl)-butan-2-one was obtained as a yellow liquid.

Source