Reaction #592847

Reaction equation

lithiumdiisopropylamide tetrahydrofuran

triethylamine

sodium hydrogencarbonate

3-Oxohexanoic acid ethyl ester

chlorotrimethylsilane

→

1-ethoxy-1,3-bis(trimethylsiloxy)hexa-1,3-diene

Yield 193.6%

Solvents

hexane

toluene

water

hexane

Conditions

Workup

1. 1
   Extractionextracted with hexane 3 times
2. 2
   Washsequentially washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine
3. 3
   Dryingdried over anhydrous sodium sulfate
4. 4
   Otherevaporated under reduced pressure
5. 5
   workup.DISSOLUTIONThe residue was dissolved in tetrahydrofuran (100 mL)
6. 6
   Temperaturecooled to −78° C
7. 7
   workup.STIRRINGby stirring at −78° C. for 1 hour
8. 8
   workup.STIRRINGthe reaction mixture was stirred at −78° C. for 8 hours
9. 9
   Extractionextracted with hexane 3 times
10. 10
    Washsequentially washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine
11. 11
    Dryingdried over anhydrous sodium sulfate
12. 12
    Otherevaporated under reduced pressure

Procedure

3-Oxohexanoic acid ethyl ester (20 mL, 0.13 mol) was dissolved in toluene (100 mL), and the obtained solution was added with triethylamine (28 mL, 0.20 mol) and chlorotrimethylsilane (24 mL, 0.19 mmol), followed by stirring at a room temperature for 4 hours. The reaction mixture was added with hexane (200 mL) and 0.5 mol/L aqueous sodium hydrogencarbonate solution and then, extracted with hexane 3 times. The organic layers were combined, sequentially washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine, dried over anhydrous sodium sulfate, and then evaporated under reduced pressure. The residue was dissolved in tetrahydrofuran (100 mL) and cooled to −78° C. The obtained solution was added with 2.0 mol/L lithiumdiisopropylamide-tetrahydrofuran solution (78 mL, 0.16 mol) followed by stirring at −78° C. for 1 hour. Then, chlorotrimethylsilane (18 mL, 0.14 mol) was added and the reaction mixture was stirred at −78° C. for 8 hours. The reaction mixture was further added with hexane (200 mL) and water and extracted with hexane 3 times. The organic layers were combined, sequentially washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine, dried over anhydrous sodium sulfate, and then evaporated under reduced pressure to obtain 1-ethoxy-1,3-bis(trimethylsiloxy)hexa-1,3-diene (41 g, 100%).

Source