Lithium cyanide → Methyl 3-cyanoandrosta-3,5-diene-17beta-carboxylate

Beteiligte Stoffe

Reaktionsschritte

3.0 g of lithium cyanide and 16 ml of diethyl cyanophosphate were dissolved in 200 ml of dry tetrahydrofuran, and 10 g of methyl 3-oxo-4-androstene-17β-carboxylate were added little by little at room temperature to the resulting solution. The reaction mixture was stirred at room temperature for 15 minutes, after which the tetrahydrofuran was removed by distillation under reduced pressure. The residue was dissolved in 300 ml of a 1:1 by volume mixture of ethyl acetate and benzene, and the resulting solution was washed four times with water and then once with a saturated aqueous solution of sodium chloride. It was then dried over anhydrous magnesium sulfate, and concentrated by evaporation under reduced pressure. The resulting residue was dissolved in 100 ml of dry benzene, and 2 ml of a boron trifluoride-diethyl ether complex was added to the resulting solution, which was then stirred at room temperature for 3 hours. At the end of this time, the reaction mixture was diluted with 300 ml of diethyl ether. The diluted mixture was washed with water, with an aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order, after which it was dried over anhydrous magnesium sulfate, and then concentrated by evaporation under reduced pressure. The resulting residue was subjected to column chromatography through 100 g of silica gel using a gradient elution method, with mixtures of ethyl acetate and hexane in ratios ranging from 4:96 to 12:88 by volume as the eluent, to give 9.5 g of the title compound.

Herkunft & Nachweise