Boron trifluoride etherate → 178167-77-6
Reaction equation
[CH3:1][C:2]1[C:7]([CH3:8])=[CH:6][CH:5]=[CH:4][C:3]=1[OH:9].B(F)(F)F.CCOCC.[CH3:19][C:20]1([CH:26]=[CH2:27])[O:25][C:23](=[O:24])[CH2:22][CH2:21]1>O1CCOCC1.CCOCC>[CH3:19][C:20]1([CH2:21][CH2:22][C:23]([OH:25])=[O:24])[CH2:26][CH2:27][C:4]2[C:3](=[C:2]([CH3:1])[C:7]([CH3:8])=[CH:6][CH:5]=2)[O:9]1Participants
Procedure
To a solution of 2,3-dimethylphenol (0.01 mol) and boron trifluoride diethyl etherate (0.016 mol) in dioxane (10 mL, dried on sodium) in a flask was added γ-methyl-γ-vinylbutyrolactone (0.016 mol) in dioxane (5.0 mL) via syringe pump over 50 min at 110° C. (oil bath, reflux) under nitrogen. The reaction mixture was cooled to room temperature and diluted with ether (200 mL), then washed with water (100 mL, 2×50 mL) and dried over sodium sulfate. Ether was then removed in vacuum. The residue was dissolved in methanol (30 mL), and solvent was removed in vacuum. The reaction mixture was purified by flash column chromatography on silica gel (eluent ethyl acetate/hexane, 1:1). Fractions containing the desired chroman were pooled, solvent was removed, and the compound was crystallized from ethyl acetate/hexane. M.P.: 93-94° C.
Workup
- temperature(oil bath, reflux) under nitrogen
- washwashed with water (100 mL, 2×50 mL)
- dry with materialdried over sodium sulfate
- customEther was then removed in vacuum
- dissolutionThe residue was dissolved in methanol (30 mL)
- customsolvent was removed in vacuum
- customThe reaction mixture was purified by flash column chromatography on silica gel (eluent ethyl acetate/hexane, 1:1)
- additionFractions containing the desired chroman
- customsolvent was removed
- customthe compound was crystallized from ethyl acetate/hexane
Sources & evidence
- ORD record
- ord-3da906a38c1847e48b8d9d4c2bf41b4e
- Source dataset
- uspto-grants-2000_07
- Patent number
- US06083982
Reaction notes
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