反応 #7933

反応方程式

4-benzyl-9a-butyl-7-methoxy-1,2,9,9a-tetrahydrofluoren-3-one

BBr3

→

4-benzyl-9a-butyl-7-hydroxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one

溶媒

CH2Cl2

CH2Cl2

反応条件

後処理

1. 1
   workup.ADDITIONwas added dropwise by syringe
2. 2
   その他The cooling bath was removed
3. 3
   workup.ADDITIONafter which it was diluted with EtOAc (8 mL), water (3 mL) and 2N HCl (1 mL)
4. 4
   workup.STIRRINGshaken vigorously
5. 5
   その他The organic phase was separated
6. 6
   洗浄washed with water (3 mL), 1M pH 3 phosphate (3 mL) and brine (3 mL)
7. 7
   乾燥dried over MgSO4
8. 8
   ろ過filtered
9. 9
   その他evaporated under vacuum to a solid (25 mg)
10. 10
    その他The crude product was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate

実験手順

A solution of 4-benzyl-9a-butyl-7-methoxy-1,2,9,9a-tetrahydrofluoren-3-one (25.9 mg, 0.718 mmol) in anhydrous CH2Cl2 (1.2 mL) was cooled in a dry ice-acetone bath and stirred under a nitrogen atmosphere while 1M BBr3 in CH2Cl2 (0.215 mL, 0.215 mmol) was added dropwise by syringe. The cooling bath was removed and the mixture was stirred at room temperature for 3.5 hours, after which it was diluted with EtOAc (8 mL), water (3 mL) and 2N HCl (1 mL) and shaken vigorously. The organic phase was separated, washed with water (3 mL), 1M pH 3 phosphate (3 mL) and brine (3 mL), dried over MgSO4, filtered and evaporated under vacuum to a solid (25 mg). The crude product was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate, using 5% MeOH in CH2Cl2 as developing solvent. The major UV visible band at Rf 0.40-0.53 gave 4-benzyl-9a-butyl-7-hydroxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one as a yellow solid.

出典