反应详情

温度

0 °C

A solution of the product obtained in Step F (20 mmol) in dichloromethane (30 ml) containing tetrabutylammonium bromide (20 mg) is cooled in an ice-bath. After the addition of sodium azide (25 mmol) dissolved in 5 ml of water, the solution is stirred vigorously at 0° C. for 2 hours. The organic phase is separated off, washed with water (2×5 ml) and dried over magnesium sulphate. After filtration, trifluoroacetic acid (30 mmol) is added and the solution is stirred under reflux for 60 hours. After cooling, the organic phase is washed with a saturated sodium hydrogen carbonate solution (2×5 ml) and concentrated under reduced pressure. The residue is then taken up in methanol (20 ml), and water (80 ml) and then potassium carbonate (30 mmol) are added. After stirring at room temperature for 20 hours, the reaction mixture is concentrated under reduced pressure to a volume of about 60 ml, and is then extracted 3 times with ether (3×50 ml). After drying over sodium sulphate, the organic phase is filtered and then evaporated under reduced pressure. The residue is chromatographed over silica gel to yield the title product.

1. temperatureis cooled in an ice-bath
2. customThe organic phase is separated off
3. washwashed with water (2×5 ml)
4. dry with materialdried over magnesium sulphate
5. additionis added
6. stirringthe solution is stirred
7. temperatureunder reflux for 60 hours
8. temperatureAfter cooling
9. washthe organic phase is washed with a saturated sodium hydrogen carbonate solution (2×5 ml)
10. concentrationconcentrated under reduced pressure
11. stirringAfter stirring at room temperature for 20 hours
12. concentrationthe reaction mixture is concentrated under reduced pressure to a volume of about 60 ml
13. extractionis then extracted 3 times with ether (3×50 ml)
14. dry with materialAfter drying over sodium sulphate
15. filtrationthe organic phase is filtered
16. customevaporated under reduced pressure
17. customThe residue is chromatographed over silica gel