Water → 4,6-Di-tert-butyl-5-hydroxy-2-methyl-2,3-dihydrobenzofuran

HRID 1900504Notes

Reaction equation

HRID 1900504 reaction equation
C([O:4][C:5]1[C:10]([C:11]([CH3:14])([CH3:13])[CH3:12])=[CH:9][C:8]([OH:15])=[C:7]([CH2:16][CH:17]=[CH2:18])[C:6]=1[C:19]([CH3:22])([CH3:21])[CH3:20])(=O)C.B(F)(F)F.O.[OH-].[Na+]>ClCCl>[C:19]([C:6]1[C:7]2[CH2:16][CH:17]([CH3:18])[O:15][C:8]=2[CH:9]=[C:10]([C:11]([CH3:14])([CH3:12])[CH3:13])[C:5]=1[OH:4])([CH3:20])([CH3:21])[CH3:22]

Participants

6

Reactant 4

HCID 962Water2×HCID 6356Boron trifluorideHCID 14798Sodium HydroxideHCID 111202654-Acetoxy-3,5-di-tert-butyl-2-(2-propenyl)phenol

Product 1

HCID 184331834,6-Di-tert-butyl-5-hydroxy-2-methyl-2,3-dihydrobenzofuranYield 52%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4-Acetoxy-3,5-di-tert-butyl-2-(2-propenyl)phenol (1.0 g, 3.3 mmol) was dissolved in dichloromethane (10 ml) and BF3 etherate (0.7 ml) was added dropwise to the solution under a nitrogen atmosphere. The mixture was stirred for 24 h at room temperature and, thereafter, water was added and the mixture was extracted with ethyl acetate. The extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate, dried over anhydrous magnesium sulfate and concentrated. The concentrate was dissolved in tetrahydrofuran (5 ml) and the solution was added dropwise to a suspension of lithium aluminum hydride (76 mg) in tetrahydrofuran (5 ml) that had been prepared under a nitrogen atmosphere. After refluxing for 3 h, the reaction mixture was cooled to room temperature and water was added dropwise. Following the addition of 1N aqueous sodium hydroxide, the mixture was subjected to extraction with diethyl ether. The organic layer was dried over anhydrous magnesium sulfate and concentrated. The concentrate was purified by silica gel chromatography (10% ethyl acetate in n-hexane) to afford 4,6-di-tert-butyl-5-hydroxy-2-methyl-2,3-dihydrobenzofuran [450 mg (yield, 52%)].

Workup

  1. extractionthe mixture was extracted with ethyl acetate
  2. washThe extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate
  3. dry with materialdried over anhydrous magnesium sulfate
  4. concentrationconcentrated
  5. dissolutionThe concentrate was dissolved in tetrahydrofuran (5 ml)
  6. additionthe solution was added dropwise to a suspension of lithium aluminum hydride (76 mg) in tetrahydrofuran (5 ml) that
  7. customhad been prepared under a nitrogen atmosphere
  8. temperatureAfter refluxing for 3 h
  9. temperaturethe reaction mixture was cooled to room temperature
  10. extractionthe mixture was subjected to extraction with diethyl ether
  11. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  12. concentrationconcentrated
  13. customThe concentrate was purified by silica gel chromatography (10% ethyl acetate in n-hexane)

Sources & evidence

ORD record
ord-b3508dc7ef394148a7554e8fd6274d07
Source dataset
uspto-grants-1996_11
Patent number
US05574178

Reaction notes

Loading…