반응 #42651

반응 방정식

acetic acid

(11β,16β)-9-fluoro-16-methyl-3,20-dioxo-11,17-bis[(trimethylsilyl)oxy]pregna-1,4-dien-21-yl acetate

tetra-n-butylammonium fluoride

→

title compound

수율 73.9%

(11β,16β)-9-fluoro-17-hydroxy-16-methyl-3,20-dioxo-11-[(trimethylsilyl)oxy]-pregna-1,4-dien-21-yl acetate

수율 73.9%

용매

tetrahydrofuran

THF

반응 조건

후처리

1. 1
   기타the ice bath was removed
2. 2
   온도to warm to room temperature
3. 3
   workup.STIRRINGstir for an additional 16 hours
4. 4
   기타Most of the THF was removed by rotary evaporation in vacuo
5. 5
   기타the residue was partitioned between ethyl acetate and water
6. 6
   세척The organic layer was washed successively with water, sat. NH4Cl, water, sat. NaHCO3, water and brine
7. 7
   건조The organic layer was dried over Na2SO4
8. 8
   여과filtered
9. 9
   기타evaporated under vacuum
10. 10
    기타to give an off-white solid
11. 11
    기타Purification by flash chromatography through a 1.6 kg column of silica gel eluting with 4% MeOH in dichloromethane

실험 절차

A solution of (11β,16β)-9-fluoro-16-methyl-3,20-dioxo-11,17-bis[(trimethylsilyl)oxy]pregna-1,4-dien-21-yl acetate (26 g, ˜43 mmol) in 430 mL of tetrahydrofuran (THF) was cooled to 0° C. and neat acetic acid (4.95 mL, 86.5 mmol) was added followed by dropwise addition of a 1.0 M solution of tetra-n-butylammonium fluoride in THF (43.3 mL, 43.3 mmol). After stirring at 0° C. for 4 hours, the ice bath was removed and the reaction was allowed to warm to room temperature and stir for an additional 16 hours. Most of the THF was removed by rotary evaporation in vacuo and the residue was partitioned between ethyl acetate and water. The organic layer was washed successively with water, sat. NH4Cl, water, sat. NaHCO3, water and brine. The organic layer was dried over Na2SO4, filtered and evaporated under vacuum to give an off-white solid. Purification by flash chromatography through a 1.6 kg column of silica gel eluting with 4% MeOH in dichloromethane provided 16.1 g of the title compound as a white solid.

출처