Boron tribromide → 1-(4-hydroxybutyl)-cyclohex-2-enyl-N,N-dimethyl-acetamide
Reaction equation
C[O:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]1([CH2:13][C:14]([N:16]([CH3:18])[CH3:17])=[O:15])[CH2:12][CH2:11][CH2:10][CH:9]=[CH:8]1.N[C@H](C(O)=O)CC1C=C2C(C=CC=C2)=CC=1.C1OCCOCCOCCOCCOC1.B(Br)(Br)Br.C([O-])(O)=O.[Na+]>C(Cl)Cl>[OH:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]1([CH2:13][C:14]([N:16]([CH3:17])[CH3:18])=[O:15])[CH2:12][CH2:11][CH2:10][CH:9]=[CH:8]1Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -30 °C
Procedure
To a solution of the relevant 2-[1-(4-methoxybutyl)-cyclohex-2-enyl]-N,N-dimethyl-acetamide isomer (5) or (5′) (51.0 g, 201 mmol), Nal (60 g, 400 mmol) and 15-crown-5 (55 g, 250 mmol) in CH2Cl2 (1000 mL) at −30 ° C. was added dropwise BBr3 (1 M solution in CH2Cl2; 241 mL, 241 mmol). The reaction mixture was stirred at −30° C. for 1 hour then a saturated NaHCO3 solution (1000 mL) was added. The organic layer was separated and the aqueous layer extracted with CH2Cl2. The combined organic layers were washed with a saturated Na2SO3 solution and dried over anhydrous MgSO4. The solvent was removed in vacuo and the residue purified over silica (gradient elution: Et2O 100% to Et2O/MeOH, 95:5) to afford 39.9 g (83% yield) of the desired product as a viscous oil which was characterized as follows:
Workup
- customThe organic layer was separated
- extractionthe aqueous layer extracted with CH2Cl2
- washThe combined organic layers were washed with a saturated Na2SO3 solution
- dry with materialdried over anhydrous MgSO4
- customThe solvent was removed in vacuo
- customthe residue purified over silica (gradient elution: Et2O 100% to Et2O/MeOH, 95:5)
Sources & evidence
- ORD record
- ord-5c32eb100cb04c86910beb2668badf8f
- Source dataset
- uspto-grants-2011_02
- Patent number
- US07888338B2
Reaction notes
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