反应详情

With ice-cooling, a solution of 40 g (326 mmol) of 9-borabicyclo[3.3.1]nonane in 650 ml of tetrahydrofuran is added over a period of 45 min to 38 g (148 mmol) of the compound from Example 13A. The mixture is stirred at this temperature for another hour, and a solution of 30 g (747 mmol) of sodium hydroxide in 740 ml of water is then added over a period of 15 min. 151 ml of a 30% strength hydrogen peroxide solution are added such that the temperature does not exceed 30° C. After the addition has ended, the cooling is removed and stirring is continued for a further 30 min. The mixture is repeatedly extracted with ethyl acetate, the combined organic phases are washed with a solution of 780 g (1.63 mol) of sodium disulphite, the organic phase is separated off and the aqueous phase is again extracted with ethyl acetate. The combined organic phases are washed with saturated sodium chloride solution, dried over magnesium sulphate and evaporated to dryness under reduced pressure. The residue is applied to silica gel and chromatographed using a gradient of cyclohexane and ethyl acetate. The product-containing fractions are combined and concentrated to dryness under reduced pressure. This gives 38 mg (93% of theory) of the desired product.

1. temperatureWith ice-cooling
2. customdoes not exceed 30° C
3. additionAfter the addition
4. customthe cooling is removed
5. stirringstirring
6. extractionThe mixture is repeatedly extracted with ethyl acetate
7. customthe organic phase is separated off
8. extractionthe aqueous phase is again extracted with ethyl acetate
9. washThe combined organic phases are washed with saturated sodium chloride solution
10. dry with materialdried over magnesium sulphate
11. customevaporated to dryness under reduced pressure
12. customchromatographed
13. concentrationconcentrated to dryness under reduced pressure