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

HRID 7837

Reaction equation

HRID 7837 reaction equation
[CH2:1]([C:8]1[C:9](=[O:27])[CH2:10][CH2:11][C:12]2([CH2:23][CH2:24][CH2:25][CH3:26])[C:20]=1[C:19]1[C:14](=[CH:15][C:16]([O:21]C)=[CH:17][CH:18]=1)[CH2:13]2)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.B(Br)(Br)Br>C(Cl)Cl>[CH2:1]([C:8]1[C:9](=[O:27])[CH2:10][CH2:11][C:12]2([CH2:23][CH2:24][CH2:25][CH3:26])[C:20]=1[C:19]1[C:14](=[CH:15][C:16]([OH:21])=[CH:17][CH:18]=1)[CH2:13]2)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 219909054-Benzyl-9a-butyl-7-methoxy-1,2,9,9a-tetrahydrofluoren-3-one

Product 1

HCID 102691454-benzyl-9a-butyl-7-hydroxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

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.

Workup

  1. additionwas added dropwise by syringe
  2. customThe cooling bath was removed
  3. additionafter which it was diluted with EtOAc (8 mL), water (3 mL) and 2N HCl (1 mL)
  4. stirringshaken vigorously
  5. customThe organic phase was separated
  6. washwashed with water (3 mL), 1M pH 3 phosphate (3 mL) and brine (3 mL)
  7. dry with materialdried over MgSO4
  8. filtrationfiltered
  9. customevaporated under vacuum to a solid (25 mg)
  10. customThe crude product was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate

Sources & evidence

ORD record
ord-704e1bcd500a470491743a4b68c37bf0
Source dataset
uspto-grants-2006_08
Patent number
US07087599B2

Linked notes

Loading…