반응 #42653

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

HCl

→

(11β,16β)-9-fluoro-11,21-dihydroxy-16-methyl-3,20-dioxopregna-1,4-dien-17-yl ethylcarbamate

수율 50.0%

용매

—

pre-mixed solution

methanol chloroform

반응 조건

후처리

1. 1
   workup.WAITAfter 5 hours more
2. 2
   기타the solution was partitioned between ethyl acetate and water
3. 3
   세척The organic phase was washed successively with sat. NaHCO3, water, and brine
4. 4
   건조The organic layer was dried over Na2SO4
5. 5
   여과filtered
6. 6
   기타evaporated in vacuo
7. 7
   기타to give a pale yellow oil
8. 8
   기타Purification by flash chromatography through a column of 500 g of silica gel
9. 9
   세척eluting with hexane/ethyl acetate/dichloromethane/methanol (3:3:3:1)

실험 절차

Solid (11β,16β)-21-(acetyloxy)-9-fluoro-16-methyl-3,20-dioxo-11-[(trimethylsilyl)oxy]-pregna-1,4-dien-17-yl ethylcarbamate (2.22 g, 3.84 mmol) was dissolved in 128 mL of a pre-mixed solution of methanol/chloroform/6N HCl (10:2:1) and stirred at room temperature. After 16 hours, an additional 2 mL of 6N HCl was added. After 5 hours more, the solution was partitioned between ethyl acetate and water. The organic phase was washed successively with sat. NaHCO3, water, and brine. The organic layer was dried over Na2SO4, filtered and evaporated in vacuo to give a pale yellow oil. Purification by flash chromatography through a column of 500 g of silica gel, eluting with hexane/ethyl acetate/dichloromethane/methanol (3:3:3:1) yielded 0.890 g of (11β,16β)-9-fluoro-11,21-dihydroxy-16-methyl-3,20-dioxopregna-1,4-dien-17-yl ethylcarbamate as a white powder.

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