反应详情

温度

-78 °C

250 mg of tert-butyl [cis-3-(tert-butyidimethylsilanyloxymethyl)cyclohexyl-methoxy]acetate are dissolved in 10 ml of abs. tetrahydrofuran and cooled to −78° C. (dry ice/acetone bath). 1.70 ml of a 2M lithium diisopropylamide solution in tetrahydrofuran/hexane are then added dropwise. The solution is initially stirred at −78° C. for 20 min and then warmed to 0° C. (ice bath), and 950 mg of methyl iodide are added. The solution is stirred at 0° C. for 1 h. 1 ml of sat. NH4Cl solution and 10 ml of water are added, and the phases are separated. The aqueous phase is extracted with ethyl acetate. The combined organic phases are dried over MgSO4 and concentrated. The crude product is dissolved in 10 ml of abs. tetrahydrofuran and cooled to −78° C. (dry ice/acetone bath). 1.70 ml of a 2M lithium diisopropylamide solution in tetrahydrofuran/hexane are then added dropwise. The solution is initially stirred at −78° C. for 20 min and then warmed to 0° C. (ice bath), and 950 mg of methyl iodide are added. The solution is stirred at 0° C. for 1 h. 1 ml of sat. NH4Cl solution and 10 ml of water are added and the phases are separated. The aqueous phase is extracted with ethyl acetate. The combined organic phases are dried over MgSO4 and concentrated. This gives 220 mg of tert-butyl 2-[cis-3-(tert-butyldimethylsilanyloxymethyl)cyclo-hexylmethoxy]-2-methylpropionate as a light-yellow oil. TLC (heptane/ethyl acetate 4/1): Rf, starting material=0.66, Rf, product=0.80.

1. additionare added
2. stirringThe solution is stirred at 0° C. for 1 h
3. customthe phases are separated
4. extractionThe aqueous phase is extracted with ethyl acetate
5. dry with materialThe combined organic phases are dried over MgSO4
6. concentrationconcentrated
7. dissolutionThe crude product is dissolved in 10 ml of abs
8. temperaturetetrahydrofuran and cooled to −78° C. (dry ice/acetone bath)
9. addition1.70 ml of a 2M lithium diisopropylamide solution in tetrahydrofuran/hexane are then added dropwise
10. stirringThe solution is initially stirred at −78° C. for 20 min
11. temperaturewarmed to 0° C. (ice bath), and 950 mg of methyl iodide
12. additionare added
13. stirringThe solution is stirred at 0° C. for 1 h
14. addition1 ml of sat. NH4Cl solution and 10 ml of water are added
15. customthe phases are separated
16. extractionThe aqueous phase is extracted with ethyl acetate
17. dry with materialThe combined organic phases are dried over MgSO4
18. concentrationconcentrated