反应详情

温度

2.5 °C

Bromine (0.0072 mL, 0.14 mmol) was added to an ice-cold mixture of (rac)-(1S,8aR)-8a-butyl-6-hydroxy-1-propyl-8,8a-dihydrocyclopenta[a]inden-2(1H)-one (40 mg, 0.14 mmol) and NaHCO3 (59 mg, 0.70 mmol) in CCl4 (0.48 mL). The resulting mixture was sonicated for 20 seconds and then stirred at 0-5° C. for 70 minutes. The mixture was diluted with CH2Cl2 (30 mL) and washed with water (30 mL), and the aqueous phase was back-extracted with CH2Cl2 (2×10 mL). The combined organics were washed with saturated aqueous Na2S2O3, dried over MgSO4, filtered, and evaporated under vacuum. The residue was purified by Biotage™ (Charlottesville, Va.) flash chromatography on a 12S (1.2×7.5 cm) silica gel column, eluting with 10:1 hexane-EtOAc, to give a clear oil. This material was further purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate (Analtech, Newark, Del.), developing twice with 5:1 hexane-EtOAc. The major UV visible band provided (rac)-(1S,8aR)-3-bromo-8a-butyl-6-hydroxy-1-propyl-8,8a-dihydrocyclopenta[a]inden-2(1H)-one as an oil.

1. customThe resulting mixture was sonicated for 20 seconds
2. washwashed with water (30 mL)
3. extractionthe aqueous phase was back-extracted with CH2Cl2 (2×10 mL)
4. washThe combined organics were washed with saturated aqueous Na2S2O3
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated under vacuum
8. customThe residue was purified by Biotage™ (Charlottesville, Va.) flash chromatography on a 12S (1.2×7.5 cm) silica gel column
9. washeluting with 10:1 hexane-EtOAc
10. customto give a clear oil
11. customThis material was further purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate (Analtech, Newark, Del.)