تفاعل #42654

معادلة التفاعل

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

المذيبات

acetonitrile

ظروف التفاعل

المعالجة

1. 1
   workup.STIRRINGThe solution was stirred at room temperature for 15 hours more
2. 2
   أخرىwas then partitioned between ethyl acetate and water
3. 3
   غسيلThe organic layer was washed with water (twice) and brine
4. 4
   تجفيفdried over Na2SO4
5. 5
   ترشيحFiltration and evaporation under vacuum
6. 6
   أخرىgave a pale yellow oil

الإجراء التجريبي

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.

المصدر