反应详情

温度

0 °C

Compound 10 (9 g, 17.84 mmol) was stirred in 100 ml of CH2Cl2 at 0° C. while 70 ml of CH2Cl2 containing HBr (3.2 g, 30.5 mmol) was added in one portion. The mixture was stirred at 0° C. for 3.5 hrs, water (55 ml) was added and the mixture stirred at r.t. for 18 hrs. The organic layer was separated, washed with sat. NaHCO3, dried (MgSO4). After evaporation of the solvent, a foam was obtained, which upon recrystallization from CH2Cl2 and n-hexane, gave 11 as a white solid. (6.2 g, 75.5%). m.p. 137°-138° C., lit. 140°-141° C., [α]D =-81.960 (c 0.55, CHCl3 ; D form: [α]D =+83.71.

1. additionwas added in one portion
2. stirringthe mixture stirred at r.t. for 18 hrs
3. customThe organic layer was separated
4. washwashed with sat. NaHCO3
5. dry with materialdried (MgSO4)
6. customAfter evaporation of the solvent
7. customa foam was obtained
8. customwhich upon recrystallization from CH2Cl2 and n-hexane