Ammonium Chloride → (7alpha,17beta)-17-(Acetyloxy)-7-ethenylestr-4-en-3-one

関与物質

反応条件

反応手順

—Vinylmagnesium chloride in tetrahydrofuran (2 M, 9.55 ml) was added dropwise to a mixture of (17β)-17-(acetyloxy)estra-4,6-dien-3-one (Example 3, step i; 3.0 g), copper(I) bromide-dimethyl sulfide complex (0.191 g), lithium bromide (0.083 g), and lithium thiophenoxide (0.96 ml of a 1 M solution in tetrahydrofuran), in dry tetrahydrofuran (10 ml), cooled to −15° C. After 25 min. stirring a saturated aqueous solution of ammonium chloride was added and the product extracted into ethyl acetate. The combined organic phases were concentrated under reduced pressure whereafter the residue was dissolved in acetone (100 ml) and treated with hydrochloric acid (4 M, 10 ml). After 30 min. stirring at room temperature, a saturated aqueous solution of sodium hydrogencarbonate was added. The product was extracted into ethyl acetate; the combined organic phases were washed with brine, dried over sodium sulfate and concentrated under reduced pressure, to give (7α,17β)-17-(acetyloxy)-7-ethenylestr-4-en-3-one (3.76 g). The product was used in the following step without further purification.

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