反应详情

Potassium tert-butoxide (1.70 g, 15 mM) and (20S)-20-hydroxymethylpregn-4-en-3-one (1.65 g, 5 mM) are mixed together in tert-butanol (25 mL), and heated at reflux temperature under argon atmosphere for 75 minutes. Iso-propylnitrate (0.51 mL, 5 mM) is then added to the refluxing reaction mixture, resulting in an exothermic reaction. After one minute, the reaction vessel is removed from heat and allowed to cool to room temperature. The cooled mixture is then made acidic by addition of acetic acid (5 mL), and stirred overnight. The mixture is then diluted with dichloromethane so as to form a separate phase sufficient to solubilize the synthesized product. Subsequently, the solids are removed by filtration and washed with dichloromethane. The materials in both the filtrate and wash(es) are combined together and concentrated. The residue is then redissolved in dichloromethane, then purified by flash chromatagraphy on silica gel to give (20S)-20-hydroxymethyl-4-nitropregn-4-en-3-one. The crystallization of this material from aqueous acetone gives white needles (m.p. 166°-168° C.).

1. temperatureheated
2. temperatureat reflux temperature under argon atmosphere for 75 minutes
3. customresulting in an exothermic reaction
4. customthe reaction vessel is removed
5. temperaturefrom heat
6. additionmade acidic by addition of acetic acid (5 mL)
7. additionThe mixture is then diluted with dichloromethane so as
8. customto form a separate phase sufficient
9. customSubsequently, the solids are removed by filtration
10. washwashed with dichloromethane
11. concentrationconcentrated
12. dissolutionThe residue is then redissolved in dichloromethane
13. custompurified by flash chromatagraphy on silica gel