反应详情

温度

5 °C

Under a nitrogen atmosphere sodium borohydride (0.53 g) and lithium aluminium hydride (0.65 g) were added to a stirred solution of ethyl (20Z)-20-formamido-9α-hydroxy-3-methoxypregna-3,5,17(20)-trien-21-oate (4.85 g, prepared according to example 10), in dry tetrahydrofuran (100 ml) at 0° C. The reaction mixture was stirred at 5° C. for 2 hours, after which another 0.54 g of sodium borohydride and 0.65 g of lithium aluminium hydride were added. Stirring was continued at 5° C. for 1.5 hours, then ethanol (50 ml) was added dropwise to decompose excess reducing agent. After adding 60 ml of an aqueous solution of sodium potassium tartrate, the reaction mixture was filtered and extracted with ethyl acetate. The organic phase was washed with an aqueous sodium carbonate solution and with water, dried (MgSO4) and concentrated under reduced pressure. The residue (3.02 g) was purified by column chromatography (toluene/acetone 2/1 containing 0,1% triethylamine) to provide 1.08 g of the title compound.

1. stirringStirring
2. waitwas continued at 5° C. for 1.5 hours
3. filtrationthe reaction mixture was filtered
4. extractionextracted with ethyl acetate
5. washThe organic phase was washed with an aqueous sodium carbonate solution and with water
6. dry with materialdried (MgSO4)
7. concentrationconcentrated under reduced pressure
8. customThe residue (3.02 g) was purified by column chromatography (toluene/acetone 2/1 containing 0,1% triethylamine)