Реакция #42653

Уравнение реакции

(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

Выход 50.0%

Растворители

—

pre-mixed solution

methanol chloroform

Условия реакции

Обработка

1. 1
   workup.WAITAfter 5 hours more
2. 2
   Другоеthe solution was partitioned between ethyl acetate and water
3. 3
   ПромывкаThe organic phase was washed successively with sat. NaHCO3, water, and brine
4. 4
   СушкаThe organic layer was dried over Na2SO4
5. 5
   Фильтрацияfiltered
6. 6
   Другоеevaporated in vacuo
7. 7
   Другоеto give a pale yellow oil
8. 8
   ДругоеPurification by flash chromatography through a column of 500 g of silica gel
9. 9
   Промывкаeluting with hexane/ethyl acetate/dichloromethane/methanol (3:3:3:1)

Методика

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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