Sodium Bicarbonate → (3beta,20R)-3-[(1-ethoxyethyl)oxy]pregn-5-en-20-ol

Beteiligte Stoffe

Reaktionsschritte

—Sodium (8.98 g) was added in small portions in the course of 2 h to a refluxing solution of (3β)-3-[(1-ethoxyethyl)oxy]pregn-5-en-20-one (20 g) in dry n-butanol (587 ml). Heating was continued for another 2 h; then the reaction mixture was cooled and poured into a saturated aqueous solution of sodium hydrogen carbonate (1.5 l). The product was extracted into ethyl acetate; the combined organic phases were washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. Column chromatography of the crude product afforded (3β,20R)-3-[(1-ethoxyethyl)oxy]pregn-5-en-20-ol (compound 3b; 5.08 g) and (3β,20S)-3-[(1-ethoxyethyl)oxy]pregn-5-en-20-ol (compound 3a; 7.21 g).

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