3-Bromo-2-methyl-1-propene → 2-(3,5-Bis-benzyloxyphenyl)-4-methyl-pent-4-enoic acid methyl ester

HRID 226508

Reaction equation

HRID 226508 reaction equation
[Li+].CC([N-]C(C)C)C.C1COCC1.CCCCCCC.[CH2:21]([C:23]1[CH:28]=CC=C[CH:24]=1)C.[CH3:29][O:30][C:31](=[O:55])[CH2:32][C:33]1[CH:38]=[C:37]([O:39][CH2:40][C:41]2[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=2)[CH:36]=[C:35]([O:47][CH2:48][C:49]2[CH:54]=[CH:53][CH:52]=[CH:51][CH:50]=2)[CH:34]=1.BrCC(C)=C>C1COCC1>[CH3:29][O:30][C:31](=[O:55])[CH:32]([C:33]1[CH:34]=[C:35]([O:47][CH2:48][C:49]2[CH:54]=[CH:53][CH:52]=[CH:51][CH:50]=2)[CH:36]=[C:37]([O:39][CH2:40][C:41]2[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=2)[CH:38]=1)[CH2:24][C:23]([CH3:28])=[CH2:21]

Participants

6

Reactant 4

HCID 3577853-Bromo-2-methyl-1-propeneHCID 640121Methyl [3,5-bis(benzyloxy)phenyl]acetateHCID 2724682Lithium diisopropylamideHCID 22742125Tetrahydrofuran heptane ethylbenzol

Product 1

HCID 577550392-(3,5-Bis-benzyloxyphenyl)-4-methyl-pent-4-enoic acid methyl esterYield 94.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A 2M solution of LDA in THF-heptane-ethylbenzene (21.5 mL, 43.0 mmol) was added dropwise over 12 min to a stirred solution of (3,5-bis-benzyloxyphenyl)acetic acid methyl ester (13.0 g, 35.9 mmol) in THF (80 mL) at −78° C. under a nitrogen atmosphere. The temperature was maintained below −70° C. for a further 50 min then 3-bromo-2-methylpropene (4.0 mL, 39.7 mmol) was added in one portion and the reaction mixture was warmed to 0° C. After 2 h the mixture was concentrated in vacuo, diluted with sat. aq. NH4Cl (100 mL) and extracted with EtOAc (100 mL). The organic layer was washed with brine (100 mL), dried (MgSO4), concentrated in vacuo and purified by flash chromatography (silica, 0-10% EtOAc in petroleum ether) to afford the title product as a yellow oil (14.1 g, 94%).

Workup

  1. temperatureThe temperature was maintained below −70° C. for a further 50 min
  2. concentrationAfter 2 h the mixture was concentrated in vacuo
  3. additiondiluted with sat. aq. NH4Cl (100 mL)
  4. extractionextracted with EtOAc (100 mL)
  5. washThe organic layer was washed with brine (100 mL)
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated in vacuo
  8. custompurified by flash chromatography (silica, 0-10% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-e4cd3a373ea64c1397c60db3820a9fa0
Source dataset
uspto-grants-2009_07
Patent number
US07557244B2

Linked notes

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