反应详情

温度

-78 °C

Under argon, the compound obtained in Example 1 (342 mg; 1.37 mmol) is dissolved in 8 ml of distilled dichloromethane. The solution is cooled to −78° C., and then boron tribromide (4 eq.; 5.47 mmol; 5.17 μl) diluted with 5 ml of dichloromethane is slowly added. The mixture is left for one hour at −78° C. and then for 2 hours at ambient temperature. The reaction mixture is hydrolysed to pH 7 with a saturated sodium hydrogen carbonate solution and then the aqueous phase is extracted 4 times with dichloromethane. The organic phases are combined, and then removed under reduced pressure. The solid obtained is dissolved in a minimum amount of dichloromethane, precipitated in the presence of pentane, filtered, and then washed with an Et2O/pentane mixture.

1. additionis slowly added
2. waitfor 2 hours at ambient temperature
3. extractionthe aqueous phase is extracted 4 times with dichloromethane
4. customremoved under reduced pressure
5. customThe solid obtained
6. customprecipitated in the presence of pentane
7. filtrationfiltered
8. washwashed with an Et2O/pentane mixture