Reacción #44478

Ecuación de reacción

O-phosphoric acid

ethyl acetate

imidazole

Tert-butyl-chloro-dimethyl-silane

Sodium borohydride

solution

1-Cycloheptyl-5-oxo-pyrrolidine-3-carboxylic acid methyl ester

→

title compound

4-(tert-Butyl-dimethyl-silanyloxymethyl)-1-cycloheptyl-pyrrolidine-2-one

Disolventes

methanol

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction was cooled to 0° C.
2. 2
   workup.STIRRINGstirred
3. 3
   FiltraciónThe reaction was filtered through a pad of celite
4. 4
   Lavadorinsed with methanol
5. 5
   Concentraciónconcentrated under vacuo
6. 6
   Lavadowashed with water (25 mL)
7. 7
   SecadoThe organic layer was dried with MgSO4
8. 8
   Filtraciónfiltered
9. 9
   Otroevaporated in vacuo
10. 10
    workup.STIRRINGstirred for three hours
11. 11
    Lavadowashed with water (50 mL) and brine (25 mL)
12. 12
    SecadoThe organic layer was dried with MgSO4
13. 13
    Filtraciónfiltered
14. 14
    Otroevaporated in vacuo
15. 15
    OtroThe crude product was purified by flash chromatography (hexanes:ethyl acetate 95:5 to 75:25)

Procedimiento

Sodium borohydride (0.213 g, 5.77 mmoles) was added to a solution of Example 1A (0.7 g, 2.92 mmoles) in methanol (3 mL) and tetrahydrofuran (3 mL) and stirred at 60° C. for two hours. The reaction was cooled to 0° C. and O-phosphoric acid (1.6 g, 17.4 mmoles) was added and stirred. The reaction was filtered through a pad of celite, rinsed with methanol, and concentrated under vacuo. The crude oil was taken up in ethyl acetate (25 mL) and washed with water (25 mL). The organic layer was dried with MgSO4, filtered and evaporated in vacuo. The resulting oil was taken up in N,N-dimethylformamide (4 mL) and imidazole (391 g, 5.76 mmoles) and Tert-butyl-chloro-dimethyl-silane (583 g, 3.88 mmoles) were added and stirred for three hours. The reaction was diluted with ethyl acetate (40 mL) and washed with water (50 mL) and brine (25 mL). The organic layer was dried with MgSO4 filtered and evaporated in vacuo. The crude product was purified by flash chromatography (hexanes:ethyl acetate 95:5 to 75:25) to give the title compound as a colorless oil.

Fuente