Reaction #452444

ord-1962acd78ae64d6f83c39c94c0ffe333

Reaction equation

C=CC(C)CCCC(C)(C)O
dihydromyrcenol
C=C1CC(=O)O1
Diketene
→
C=CC(C)CCCC(C)(C)OC(=O)CC(C)=O
desired product
Yield 95.0%
C=CC(C)CCCC(C)(C)OC(=O)CC(C)=O
2,6-dimethyl-7-octen-2-yl 3-oxo-butyrate
Yield 95.0%

Reactants

C=CC(C)CCCC(C)(C)O
dihydromyrcenol
C=C1CC(=O)O1
Diketene

Reagents

CN(C)c1ccncc1
4-dimethylaminopyridine

Conditions

Temperature
55°CELSIUS
Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    Otherfitted with a condenser, argon inlet, addition funnel, magnetic stirrer
  2. 2
    Temperaturethe mixture is cooled to room temperature
  3. 3
    OtherPurification of the product mixture
  4. 4
    Washby flash chromatography (elution with dichloromethane)

Procedure

A mixture of dihydromyrcenol (37.88 g, 0.240 mol) and 4-dimethylaminopyridine (0.16 g, 1.30 mmol) in a 100 mL three-necked round-bottomed flask fitted with a condenser, argon inlet, addition funnel, magnetic stirrer and internal thermometer is heated to 50-60° C. Diketene (20.16 g, 0.240 mol) is added dropwise in the course of 15 min. The mixture has a slight exotherm and turned from yellow to red during this time. After stirring an additional hour at 50° C., the mixture is cooled to room temperature. At this point, NMR analysis indicates the reaction is complete. Purification of the product mixture by flash chromatography (elution with dichloromethane) yields the desired product in 95% yield as a nearly colorless oil.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US06126953uspto-grants-2000_10