Reaction #42655

Reaction equation

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

→

(11β,16β)-9-fluoro-11,21-dihydroxy-16-methyl-3,20-dioxopregna-1,4-dien-17-yl (1R)-1-phenylethylcarbamate

Yield 57.9%

Solvents

—

pre-mixed solution

methanol chloroform

Conditions

Workup

1. 1
   OtherThe solution was then partitioned between ethyl acetate and water
2. 2
   Washthe organic phase was washed with water (twice) and brine
3. 3
   Dryingdried over Na2SO4
4. 4
   FiltrationFiltration and evaporation under vacuum
5. 5
   Othergave a white film which
6. 6
   Otherwas purified by preparative thin layer chromatography on silica gel
7. 7
   Washeluting with ethyl acetate/hexane/dichloromethane/methanol (95:95:95:15)

Procedure

(11β,16β)-21-(acetyloxy)-9-fluoro-11-hydroxy-16-methyl-3,20-dioxopregna-1,4-dien-17-yl (1R)-1-phenylethylcarbamate (42 mg, 0.064 mmol) was dissolved in 1.25 mL of a pre-mixed solution of methanol/chloroform/6N HCl (10:2:1) and stirred at room temperature for 24.5 hours. The solution was then partitioned between ethyl acetate and water and the organic phase was washed with water (twice) and brine and dried over Na2SO4. Filtration and evaporation under vacuum gave a white film which was purified by preparative thin layer chromatography on silica gel, eluting with ethyl acetate/hexane/dichloromethane/methanol (95:95:95:15), to yield 20 mg of (11β,16β)-9-fluoro-11,21-dihydroxy-16-methyl-3,20-dioxopregna-1,4-dien-17-yl (1R)-1-phenylethylcarbamate as a white solid.

Source