Methanol → Methyl 2,4-bis-benzyloxy-5-isopropenylbenzoate

HRID 41380Notes

Reaction equation

HRID 41380 reaction equation
[CH2:1]([Li])[CH2:2][CH2:3][CH3:4].[C:6]([C:9]1[C:10]([O:27][CH2:28][C:29]2[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=2)=[CH:11][C:12]([O:19]CC2C=CC=CC=2)=[C:13]([CH:18]=1)[C:14]([O:16][CH3:17])=[O:15])(=O)[CH3:7].[CH3:35]O.O1C[CH2:40][CH2:39][CH2:38]1>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[CH2:1]([O:19][C:12]1[CH:11]=[C:10]([O:27][CH2:28][C:29]2[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=2)[C:9]([C:6]([CH3:35])=[CH2:7])=[CH:18][C:13]=1[C:14]([O:16][CH3:17])=[O:15])[C:2]1[CH:40]=[CH:39][CH:38]=[CH:4][CH:3]=1

Participants

6

Conditions

Temperature
0 °C

Procedure

A stirred suspension of methyltriphenylphosphonium bromide (1.96 g, 5.5 mmol) in anhydrous tetrahydrofuran (20 ml) at 0° C. under a nitrogen atmosphere was treated dropwise with n-butyl lithium (1.6 M in hexanes, 3.5 ml, 5.5 mmol) and the resulting bright yellow solution was stirred at 0° C. for 30 minutes. A solution of methyl 5-acetyl-2,4-bis-benzyloxybenzoate (1.95 g, 5.00 mmol) in anhydrous tetrahydrofuran (20 ml) was added dropwise and the resulting mixture was allowed to warm to room temperature and was stirred for 16 hours. Methanol (10 ml) was added and the solvent was removed in vacuo. The residues were partitioned between dichloromethane and water, the organic layer was separated and the solvent removed in vacuo to afford a brown gum that was purified by column chromatography on silica. Elution with 7% ethyl acetate in petroleum ether afforded methyl 2,4-bis-benzyloxy-5-isopropenyl-benzoate as a colourless solid (700 mg, 36%). 1H NMR (DMSO-d6) 7.59 (1H, s), 7.52 (2H, d), 7.64-7.32 (8H, m), 6.97 (1H, s), 5.28 (2H, s), 5.22 (2H, s), 5.09 (1H, s), 5.04 (1H, s), 3.76 (3H, s), 2.02 (3H, s). MS: [M+H]+ 389.

Workup

  1. temperatureto warm to room temperature
  2. stirringwas stirred for 16 hours
  3. customthe solvent was removed in vacuo
  4. customThe residues were partitioned between dichloromethane and water
  5. customthe organic layer was separated
  6. customthe solvent removed in vacuo
  7. customto afford a brown gum that
  8. customwas purified by column chromatography on silica
  9. washElution with 7% ethyl acetate in petroleum ether

Sources & evidence

ORD record
ord-7ecd8e2e2a5d457cb7013fe620309808
Source dataset
uspto-grants-2013_09
Patent number
US08530469B2

Reaction notes

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