Phosphorus tribromide → (2E,6E)-1-bromo-3,7,11-trimethyldodeca-2,6,10-triene
Reaction equation
O[CH2:2]/[CH:3]=[C:4](/[CH2:6][CH2:7]/[CH:8]=[C:9](/[CH2:11][CH2:12][CH:13]=[C:14]([CH3:16])[CH3:15])\[CH3:10])\[CH3:5].P(Br)(Br)[Br:18]>CCOCC>[CH3:5]/[C:4](/[CH2:6][CH2:7]/[CH:8]=[C:9](\[CH3:10])/[CH2:11][CH2:12][CH:13]=[C:14]([CH3:16])[CH3:15])=[CH:3]\[CH2:2][Br:18]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of 1.00 g (4.5 mmol) of (E,E)-farnesol (Aldrich, further purified by flash chromatography) in 10 mL of distilled ether at 0° C. under argon in the dark was treated dropwise with a solution of 195 μL (2.05 mmol, 0.45 eq.) of PBr3 in 2 mL of diethyl ether (ether). The resultant mixture was stirred at 0° C. for one hour, then quenched with water and separated. The organic phase was washed with 5 mL of H2O, 5 mL of saturated NaHCO3, and 5 mL of brine, dried over Na2SO4 and evaporated to give 1.26 g (98%) of crude bromide as a clear oil.