Phosphorus tribromide → (2E,6E)-1-bromo-3,7,11-trimethyldodeca-2,6,10-triene

HRID 466633

Reaction equation

HRID 466633 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

HCID 24614Phosphorus tribromideHCID 445070Farnesol

Product 1

HCID 5366048(2E,6E)-1-bromo-3,7,11-trimethyldodeca-2,6,10-trieneYield 215.5%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

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.

Workup

  1. customquenched with water
  2. customseparated
  3. washThe organic phase was washed with 5 mL of H2O, 5 mL of saturated NaHCO3, and 5 mL of brine
  4. dry with materialdried over Na2SO4
  5. customevaporated

Sources & evidence

ORD record
ord-6c8f3362e2fb45108153ea11e527a16a
Source dataset
uspto-grants-1992_10
Patent number
US05157027

Linked notes

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