反应详情

After adding 22 ml of a 10% strength potassium hydroxide solution, a solution of 2.3 g of 18,18-difluoro-androst-5-ene-3β,17β-diol diacetate (crude product) in 130 ml of methanol is stirred for 1 hour at room temperature, whilst passing nitrogen through the solution. The reaction mixture is then concentrated to about 60 ml in an aspirator vacuum and taken up in ethyl acetate and the mixture is washed with 1 N hydrochloric acid and with water until neutral, dried and evaporated in an aspirator vacuum. The crude 18,18-difluoro-androst-5-ene-3β,17β-diol is suspended, without purification, in 80 ml of toluene, the suspension is treated with 8 ml of cyclohexanone and 2.2 g of aluminium isopropylate and the mixture is refluxed for 45 minutes with stirring. The cooled reaction mixture is worked up by diluting it with ethyl acetate and washing it successively with saturated Seignette salt solution (potassium sodium tartrate solution) and with water. The washings are further extracted with ethyl acetate and the organic phases are dried and evaporated in an aspirator vacuum. The amorphous residue is then chromatographed over 100 times the amount by weight of silica gel. Elution with a mixture of hexane/ethyl acetate (3:1) gives successively, in approximately equal amounts by weight, 18,18-difluoro-androst-4-ene-3,17-dione, which after recrystallisation from acetone/hexane melts at 161°-163° C, and 18,18-difluoro-17β-hydroxy-androst-4-en-3-one of melting point 183°-184° C (recrystallised from acetone/hexane).

1. concentrationThe reaction mixture is then concentrated to about 60 ml in an aspirator vacuum
2. washthe mixture is washed with 1 N hydrochloric acid and with water until neutral,
3. customdried
4. customevaporated in an aspirator vacuum
5. customThe crude 18,18-difluoro-androst-5-ene-3β,17β-diol is suspended, without purification, in 80 ml of toluene
6. additionthe suspension is treated with 8 ml of cyclohexanone and 2.2 g of aluminium
7. temperaturethe mixture is refluxed for 45 minutes
8. customThe cooled reaction mixture
9. washwashing it successively with saturated Seignette salt solution (potassium sodium tartrate solution)
10. extractionThe washings are further extracted with ethyl acetate
11. customthe organic phases are dried
12. customevaporated in an aspirator vacuum
13. customThe amorphous residue is then chromatographed over 100 times the amount by weight of silica gel
14. washElution
15. additionwith a mixture of hexane/ethyl acetate (3:1)