Reaction #452442

Reaction equation

nonanoyl chloride

3,7-dimethyl-1,6-octadien-3-yl acetate

Lithium diisopropylamide

→

desired product

3,7-dimethyl-1,6-octadien-3-yl 3-(nonanyl)-3-oxo-propionate

Solvents

THF

Conditions

Workup

1. 1
   Otherfitted with a magnetic stirrer
2. 2
   workup.ADDITIONinternal thermometer, argon inlet, and addition funnel
3. 3
   workup.ADDITIONthe resulting solution added to the flask over 45 min
4. 4
   workup.ADDITIONOnce addition
5. 5
   TemperatureThe mixture is warmed to -20° C.
6. 6
   workup.STIRRINGstirred at that temperature for 18 h
7. 7
   TemperatureAfter warming to 0° C.
8. 8
   Otherthe mixture is quenched with 20% HCl (60 mL)
9. 9
   workup.ADDITIONThe mixture is poured into a separatory funnel
10. 10
    workup.ADDITIONcontaining ether (150 mL) and water (250 mL)
11. 11
    ExtractionThe aqueous layer is extracted with ether (150 mL)
12. 12
    WashThe combined organic layers are washed with saturated NaHCO3 solution (2×100 mL), water (2×150 mL) and brine (150 mL)
13. 13
    Dryingdried over MgSO4
14. 14
    Filtrationfiltered
15. 15
    OtherThe solvent is removed by rotary evaporation
16. 16
    Otherto give an orange/red oil
17. 17
    OtherThe oil is purified by column chromatography (elution with 2% ethyl acetate/petroleum ether)
18. 18
    Otherto yield a colorless oil

Procedure

Lithium diisopropylamide (133.7 mL of a 2.0 M solution, 0.267 mol) is placed into a 500 mL three-necked round-bottomed flask fitted with a magnetic stirrer, internal thermometer, argon inlet, and addition funnel. The flask is cooled to -78° C. 3,7-dimethyl-1,6-octadien-3-yl acetate (24.73 g, 0.126 mol) is dissolved in THF (40 mL) and the resulting solution added to the flask over 45 min. Once addition is complete, the mixture is stirred for an additional 15 min. before being treated with a solution of nonanoyl chloride (21.88 g, 0.119 mol) over 30 min. The mixture is warmed to -20° C. and stirred at that temperature for 18 h. After warming to 0° C., the mixture is quenched with 20% HCl (60 mL). The mixture is poured into a separatory funnel containing ether (150 mL) and water (250 mL). The aqueous layer is extracted with ether (150 mL). The combined organic layers are washed with saturated NaHCO3 solution (2×100 mL), water (2×150 mL) and brine (150 mL), dried over MgSO4 and filtered. The solvent is removed by rotary evaporation to give an orange/red oil. The oil is purified by column chromatography (elution with 2% ethyl acetate/petroleum ether) to yield a colorless oil having 1H and 13C NMR spectra consistent with the desired product.

Source