反应详情

A solution of 8a-butyl-6-methoxy-8,8a-dihydrocyclopenta[a]inden-2(1H)-one (37 mg, 0.14 mmol) in anhydrous CH2Cl2 (1.4 mL) was placed under a nitrogen atmosphere, cooled in a dry ice-acetone bath, and treated over two minutes with 1M BBr3 in CH2Cl2 (0.42 mL, 0.42 mmol). The cooling bath was removed and the reaction mixture was stirred at room temperature for 3 hours. Additional 1M BBr3 in CH2Cl2 (0.1 mL, 0.1 mmol) was added and the mixture was stirred at room temperature overnight. The mixture was partitioned between EtOAc and aqueous 1N HCl. The organic phase was washed with 5% NaHCO3 and brine, dried over MgSO4, filtered, and evaporated under vacuum to provide a solid residue. Recrystallization of this material from hot EtOAc gave pure 8a-butyl-6-hydroxy-8,8a-dihydrocyclopenta[a]inden-2(1H)-one (11 mg). Concentration of the mother liquors gave additional product contaminated with ˜5% of starting material.

1. temperaturecooled in a dry ice-acetone bath
2. customThe cooling bath was removed
3. stirringthe mixture was stirred at room temperature overnight
4. customThe mixture was partitioned between EtOAc and aqueous 1N HCl
5. washThe organic phase was washed with 5% NaHCO3 and brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. customevaporated under vacuum
9. customto provide a solid residue
10. customRecrystallization of this material from hot EtOAc