Boron tribromide → 1-(4-hydroxybutyl)-cyclohex-2-enyl-N,N-dimethyl-acetamide

Participants

Reaction Conditions

Reaction Steps

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:

Provenance & Evidence