1-Chloro-3-methyl-2-butene → 3,3,6-Trimethylhepta-1,5-dien-4-one

HRID 543907Notes

Reaction equation

HRID 543907 reaction equation
[Mg].[CH2:2](Cl)[CH:3]=[C:4]([CH3:6])[CH3:5].[CH3:8][C:9]([CH3:14])=[CH:10][C:11](Cl)=[O:12]>O1CCCC1.CC(C)=CCCl>[CH3:5][C:4]([CH3:6])([C:11](=[O:12])[CH:10]=[C:9]([CH3:14])[CH3:8])[CH:3]=[CH2:2]

Participants

6

Reactant 3

HCID 104291-Chloro-3-methyl-2-buteneHCID 1023943-Methyl-2-butenoyl chlorideHCID 5462224Magnesium

Product 1

HCID 683463,3,6-Trimethylhepta-1,5-dien-4-one

Reagents, catalysts & solvents 2

HCID 104291-Chloro-3-methyl-2-buteneCatalystHCID 8028TetrahydrofuranSolvent4×

Procedure

3 g of 3-methyl-but-2-enyl chloride (prenyl chloride) were added, under stirring, to a suspension of magnesium turnings (20 g; 0.83 M) in 100 ml of absolute tetrahydrofurane (THF). After initiation of the reaction, there were still added 900 ml of THF and the whole mixture was then cooled to -5°. A solution of 80 g of prenyl chloride in 400 ml of THF was then added to the above mixture which was finally kept at 10° for 3 hours. After cooling to 0°, a solution of 83 g. (0.7 M) of 3-methyl-but-2-en-1-oyl chloride in 350 ml of THF was added thereto and, after having been kept at room temperature for 3 further hours, the reaction mixture was poured onto ice-water. After evaporation of the volatile parts (THF) under reduced pressure, the concentrated residue was extracted twice with diethyl ether and the combined organic extracts washed with water, then neutralized with sodium hydrogencarbonate, dried and concentrated. The crude material thus obtained was finally distilled through a VIGREUX column to yield 55.0 g of 3,3,6-trimethyl-hepta-1,5-dien-4-one having b.p. 70°-75°/11 Torr.

Workup

  1. customAfter initiation of the reaction, there
  2. temperaturethe whole mixture was then cooled to -5°
  3. temperatureAfter cooling to 0°
  4. customafter having been kept at room temperature for 3 further hours
  5. additionthe reaction mixture was poured onto ice-water
  6. customAfter evaporation of the volatile parts (THF) under reduced pressure
  7. extractionthe concentrated residue was extracted twice with diethyl ether
  8. washthe combined organic extracts washed with water
  9. customdried
  10. concentrationconcentrated
  11. customThe crude material thus obtained
  12. distillationwas finally distilled through a VIGREUX column

Sources & evidence

ORD record
ord-6df5b165dd2a45e3b0ce5e05a857f6a4
Source dataset
uspto-grants-1984_05
Patent number
US04447627

Reaction notes

Loading…