反应 #42653

反应方程式

(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

收率 50.0%

溶剂

—

pre-mixed solution

methanol chloroform

反应条件

后处理

1. 1
   workup.WAITAfter 5 hours more
2. 2
   其他the solution was partitioned between ethyl acetate and water
3. 3
   洗涤The organic phase was washed successively with sat. NaHCO3, water, and brine
4. 4
   干燥The organic layer was dried over Na2SO4
5. 5
   过滤filtered
6. 6
   其他evaporated in vacuo
7. 7
   其他to give a pale yellow oil
8. 8
   其他Purification by flash chromatography through a column of 500 g of silica gel
9. 9
   洗涤eluting with hexane/ethyl acetate/dichloromethane/methanol (3:3:3:1)

实验过程

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.

来源