Boron tribromide → (9SR,9aSR)-7-hydroxy-4-methyl-9-propyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

HRID 7878Notes

Reaction equation

HRID 7878 reaction equation
C[O:2][C:3]1[CH:15]=[C:14]2[C:6]([C:7]3[CH:12]([CH:13]2[CH2:16][CH2:17][CH3:18])[CH2:11][CH2:10][C:9](=[O:19])[C:8]=3[CH3:20])=[CH:5][CH:4]=1.B(Br)(Br)Br>C(Cl)Cl>[OH:2][C:3]1[CH:15]=[C:14]2[C:6]([C:7]3[CH:12]([CH:13]2[CH2:16][CH2:17][CH3:18])[CH2:11][CH2:10][C:9](=[O:19])[C:8]=3[CH3:20])=[CH:5][CH:4]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 67400552HCID 67400552, compound

Product 1

HCID 9943055(9SR,9aSR)-7-hydroxy-4-methyl-9-propyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of (9SR,9aSR)-7-methoxy-4-methyl-9-propyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (38.3 mg, 0.142 mmol) in anhydrous CH2Cl2 (1.1 mL) was placed under a nitrogen atmosphere, cooled in a dry ice-acetone bath, and stirred while 1M BBr3 in CH2Cl2 (0.354 mL, 0.345 mmol) was added by syringe. The cooling bath was removed and the reaction mixture was stirred at room temperature for 2.6 hours, then diluted with 0.2N HCl (5 mL) and EtOAc (10 mL) and shaken. The organic phase was separated, washed with brine, dried over MgSO4, filtered, and evaporated under vacuum to a solid (35.2 mg). The crude product was purified by flash chromatography on EM silica gel 60 (230-400 mesh, 1×18 cm column) using 3:1 hexanes-EtOAc as eluting solvent, collecting 3 mL fractions. Fractions 12-26 were combined and concentrated under vacuum to approximately 1 mL of a suspension. The suspension was filtered and the solid portion washed with EtOAc and dried under vacuum to afford (9SR,9aSR)-7-hydroxy-4-methyl-9-propyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one.

Workup

  1. temperaturecooled in a dry ice-acetone bath
  2. additionwas added by syringe
  3. customThe cooling bath was removed
  4. additiondiluted with 0.2N HCl (5 mL) and EtOAc (10 mL)
  5. stirringshaken
  6. customThe organic phase was separated
  7. washwashed with brine
  8. dry with materialdried over MgSO4
  9. filtrationfiltered
  10. customevaporated under vacuum to a solid (35.2 mg)
  11. customThe crude product was purified by flash chromatography on EM silica gel 60 (230-400 mesh, 1×18 cm column)
  12. washas eluting solvent
  13. customcollecting 3 mL fractions
  14. concentrationconcentrated under vacuum to approximately 1 mL of a suspension
  15. filtrationThe suspension was filtered
  16. washthe solid portion washed with EtOAc
  17. customdried under vacuum

Sources & evidence

ORD record
ord-7dd6343aeafb46f08ecf5adfe3390eb6
Source dataset
uspto-grants-2006_08
Patent number
US07087599B2

Reaction notes

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