反応 #42653

反応方程式

(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

収率 50.0%

溶媒

—

pre-mixed solution

methanol chloroform

反応条件

後処理

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

実験手順

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.

出典