反应详情

2.6 ml of a solution of 5% by weight sulphur dioxide in methanesulphonic acid chloride are added to a solution of 1.75 g of 3β-acetoxy-11β-hydroxy-15β,16β-methyleneandrost-5-en-17-one in 10.5 ml of dimethylformamide and 3.5 ml of γ-collidine and the whole is stirred for 20 minutes, the internal temperature being allowed to rise to approximately 45°. While stirring, the mixture, including the precipitate that has formed, is poured onto 17.5 ml of ice-water and stirring is continued for a further 10 minutes. The oil that separates out is taken up in ethyl acetate and washed in succession with saturated sodium chloride solution, ice-cold dilute hydrochloric acid, ice-cold dilute sodium hydroxide solution and again with saturated sodium chloride solution. Evaporation of the solvent yields 3β-acetoxy-15β,16β-methyleneandrosta-5,9(11)-dien-17-one that is uniform according to thin-layer chromatography and is processed further without purification.

1. customto rise to approximately 45°
2. stirringWhile stirring
3. customhas formed
4. stirringstirring
5. waitis continued for a further 10 minutes
6. washwashed in succession with saturated sodium chloride solution, ice-cold dilute hydrochloric acid, ice-cold dilute sodium hydroxide solution and again with saturated sodium chloride solution
7. customEvaporation of the solvent