反応 #7989

反応方程式

9a-butyl-4-ethyl-6-fluoro-7-methoxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

boron tribromide

→

9a-butyl-4-ethyl-6-fluoro-7-hydroxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

溶媒

dichloromethane

dichloromethane

反応条件

後処理

1. 1
   その他The cooling bath was removed
2. 2
   その他The mixture was partitioned between EtOAc (20 mL) and water (20 mL)
3. 3
   workup.ADDITIONcontaining 2N HCl (2 mL)
4. 4
   洗浄The organic phase was washed with brine (10 mL)
5. 5
   乾燥dried over MgSO4
6. 6
   ろ過filtered
7. 7
   その他evaporated under vacuum
8. 8
   その他The residue was purified by preparative layer chromatography on two 0.05×20×20 cm silica gel GF plates
9. 9
   洗浄The product bands were eluted with EtOAc
10. 10
    その他the eluent evaporated under vacuum

実験手順

A solution of 9a-butyl-4-ethyl-6-fluoro-7-methoxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (93 mg, 0.28 mmol) in anhydrous dichloromethane (1.4 mL) was cooled in a dry ice-acetone bath (−78° C.) and the solution treated with 1M boron tribromide in dichloromethane (1.4 mL, 1.4 mmol). The cooling bath was removed and the mixture was stirred at room temperature for 90 minutes. The mixture was partitioned between EtOAc (20 mL) and water (20 mL) containing 2N HCl (2 mL). The organic phase was washed with brine (10 mL), dried over MgSO4, filtered, and evaporated under vacuum. The residue was purified by preparative layer chromatography on two 0.05×20×20 cm silica gel GF plates, developing with 5% EtOAc in CH2Cl2. The product bands were eluted with EtOAc, the eluent evaporated under vacuum, and the residue lyophilized from benzene to afford 9a-butyl-4-ethyl-6-fluoro-7-hydroxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one as an amorphous solid.

出典