Ethyl orthoformate → 3-Ethoxy-13-ethylgona-3,5-dien-17-one

Participants

Reaction Steps

—Pyridinium-toluenesulfonate (5.0 g) was added to a solution of 13-ethylgon-4-ene-3,17-dione [Hoffmann-La Roche and Co.; AG, DE 1806410 (1967); 100.0 g] in a mixture of ethanol (600 ml), dioxane (800 ml) and triethyl orthoformate (199 ml). After 4.5 h stirring at room temperature pyridine (100 ml) was added and the reaction mixture was poured into a saturated aqueous solution of sodium hydrogencarbonate. The product was extracted into ethyl acetate; the combined organic phases were washed with water and brine, dried over magnesium sulfate and concentrated under reduced pressure, to give 3-ethoxy-13-ethylgona-3,5-dien-17-one (146.3 g). The product was used in the following step without further purification.

Provenance & Evidence