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

HRID 426337

Reaktionsgleichung

Reaktionsgleichung von HRID 426337
[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]

Komponenten

6

Edukt 4

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

Produkt 1

HCID 577550392-(3,5-Bis-benzyloxyphenyl)-4-methyl-pent-4-enoic acid methyl esterAusbeute 94,3 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

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 (prepared in Example 1, step (a)) (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 an additional 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 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%). 1H-NMR (400 MHz, CDCl3): δ 7.42-7.25 (m, 10H), 6.58 (s, 2H), 6.52 (s, 1H), 5.02 (s, 4H), 4.74 (s, 1H), 4.66 (s, 1H), 3.74 (t, 1H), 3.64 (s, 3H), 2.79 (dd, 1H), 2.38 (dd, 1H), 1.70 (s, 3H).

Aufarbeitung

  1. temperatureThe temperature was maintained below −70° C. for an additional 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 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)

Quellen und Nachweise

ORD-Eintrag
ord-e433833dda3c4dd5ace61102ec1f1ee3
Quelldatensatz
uspto-grants-2012_01
Patentnummer
US08106236B2

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