Hexane → 6-[(Z)-2-(3,4,5-Trimethoxyphenyl)vinyl]-1,2-di(tert-butyldimethylsilyloxy) benzene

HRID 218241Notes

Reaction equation

HRID 218241 reaction equation
[Br-].[CH3:2][O:3][C:4]1[CH:5]=[C:6]([CH:9]=[C:10]([O:14][CH3:15])[C:11]=1[O:12][CH3:13])[CH2:7][PH3+].C([Li])CCC.CCCCCC.[Si:27]([O:34][C:35]1[C:42]([O:43][Si:44]([C:47]([CH3:50])([CH3:49])[CH3:48])([CH3:46])[CH3:45])=[CH:41][CH:40]=[CH:39][C:36]=1[CH:37]=O)([C:30]([CH3:33])([CH3:32])[CH3:31])([CH3:29])[CH3:28]>O1CCCC1.O>[CH3:2][O:3][C:4]1[CH:5]=[C:6](/[CH:7]=[CH:37]\[C:36]2[C:35]([O:34][Si:27]([C:30]([CH3:33])([CH3:31])[CH3:32])([CH3:29])[CH3:28])=[C:42]([O:43][Si:44]([C:47]([CH3:50])([CH3:49])[CH3:48])([CH3:45])[CH3:46])[CH:41]=[CH:40][CH:39]=2)[CH:9]=[C:10]([O:14][CH3:15])[C:11]=1[O:12][CH3:13]

Participants

7

Reactant 4

HCID 8058HexaneHCID 233739753,4,5-Trimethoxybenzylphosphonium bromideHCID 859965232,3-Di(tert-butyldimethylsilyloxy)benzaldehydeHCID 178418339Butyllithium

Product 1

HCID 601306896-[(Z)-2-(3,4,5-Trimethoxyphenyl)vinyl]-1,2-di(tert-butyldimethylsilyloxy) benzene

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-40 °C

Procedure

A suspension of 3,4,5-trimethoxybenzylphosphonium bromide (1.047 g, 2 mmol) in 12 mL dry tetrahydrofuran was stirred under nitrogen while cooling to −40° C. then adding 1.52 mL of 1.6M butyllithium in hexane (2.44 mmol) dropwise over six minutes below −25° C. The mixture was kept at −15° C. for ten minutes before cooling to −70°. 7 (0.748 g, 2.04 mmol) was added as a solution in 3 mL THF dropwise below −60° C. and the pale orange solution allowed to reach 20° C. over a period of one hour. After stirring for a further three hours the mixture was allowed to stand overnight. Water (8.5 mL) was added slowly and the mixture extracted three times with 8.5 mL t-butyl methyl ether. The organics were washed with brine, dried and evaporated at 30° C. The crude was purified by flash chromatography (cyclohexane:AcOEt 95:5) after removing triphenylphosphine oxide by filtration to give a colourless oil 8 which solidified on standing (0.70 g):

Workup

  1. waitThe mixture was kept at −15° C. for ten minutes
  2. temperaturebefore cooling to −70°
  3. stirringAfter stirring for a further three hours the mixture
  4. waitto stand overnight
  5. extractionthe mixture extracted three times with 8.5 mL t-butyl methyl ether
  6. washThe organics were washed with brine
  7. customdried
  8. customevaporated at 30° C
  9. customThe crude was purified by flash chromatography (cyclohexane:AcOEt 95:5)
  10. customafter removing triphenylphosphine oxide
  11. filtrationby filtration

Sources & evidence

ORD record
ord-b2601a85ba8e432a92aa1d290cc9cea2
Source dataset
uspto-grants-2012_06
Patent number
US08198302B2

Reaction notes

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