反応 #42654

反応方程式

boron trifluoride etherate

hexane ethyl acetate dichloromethane methanol

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

boron trifluoride etherate

→

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

溶媒

acetonitrile

反応条件

後処理

1. 1
   workup.STIRRINGThe solution was stirred at room temperature for 15 hours more
2. 2
   その他was then partitioned between ethyl acetate and water
3. 3
   洗浄The organic layer was washed with water (twice) and brine
4. 4
   乾燥dried over Na2SO4
5. 5
   ろ過Filtration and evaporation under vacuum
6. 6
   その他gave a pale yellow oil

実験手順

To a solution of (11β,16β)-21-(acetyloxy)-9-fluoro-16-methyl-3,20-dioxo-11-[(trimethylsilyl)-oxy]pregna-1,4-dien-17-yl ethylcarbamate (138 mg, 0.239 mmol) in 2.5 mL of acetonitrile was added boron trifluoride etherate (0.12 mL, 0.96 mmol). After stirring at room temperature for 5 hours, additional boron trifluoride etherate (0.060 mL, 0.47 mmol) was added. The solution was stirred at room temperature for 15 hours more and was then partitioned between ethyl acetate and water. The organic layer was washed with water (twice) and brine and dried over Na2SO4. Filtration and evaporation under vacuum gave a pale yellow oil. Chromatography on silica gel eluting with hexane/ethyl acetate/dichloromethane/methanol (5:2:2:1) gave (11β,16β)-21-(acetyloxy)-9-fluoro-11-hydroxy-16-methyl-3,20-dioxopregna-1,4-dien-17-yl ethylcarbamate as a white film.

出典