Acetonyltriphenylphosphonium bromide → methyl (1R,trans) 2,2-dimethyl-3-[(E)-3-oxo-1-butenyl]-cyclopropane-1-carboxylate

HRID 1388257

Reaktionsgleichung

Reaktionsgleichung von HRID 1388257
[CH3:1][C:2]1([CH3:11])[C@H:4]([CH:5]=O)[C@H:3]1[C:7]([O:9][CH3:10])=[O:8].[Br-].[O:13]=[C:14]([CH3:35])[CH2:15][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>ClC(Cl)C>[CH3:1][C:2]1([CH3:11])[C@H:4](/[CH:5]=[CH:15]/[C:14](=[O:13])[CH3:35])[C@H:3]1[C:7]([O:9][CH3:10])=[O:8]

Komponenten

4

Edukt 2

HCID 638158Acetonyltriphenylphosphonium bromideHCID 11040927Methyl trans-3-formyl-2,2-dimethylcyclopropanecarboxylate

Produkt 1

HCID 86739223methyl (1R,trans) 2,2-dimethyl-3-[(E)-3-oxo-1-butenyl]-cyclopropane-1-carboxylateAusbeute 80,3 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 63651,1-DichloroethaneLösungsmittel

Versuchsvorschrift

A mixture of 5 g of methyl (1R,trans) 2,2-dimethyl-3-formyl-cyclopropane-1-carboxylate, 11.3 g of 2-oxopropyl-triphenylphosphonium bromide and 50 ml of dichloroethane was refluxed for 2 hours and the temperature was allowed to return to room temperature. The mixture was evaporated to dryness under reduced pressure and the 19 g of oil residue were empasted with ether and filtered. The filtrate was evaporated to dryness and the 5 g of oil residue were chromatographed over silica gel. Elution with a 7-3 cyclohexane-ethyl acetate mixture yielded 4.46 g of methyl (1R,trans) 2,2-dimethyl-3-[(E)-3-oxo-1-butenyl]-cyclopropane-1-carboxylate with a specific rotation of [α]D20 =+108°±2.5° (c=0.6% in benzene).

Aufarbeitung

  1. temperaturewas refluxed for 2 hours
  2. customto return to room temperature
  3. customThe mixture was evaporated to dryness under reduced pressure
  4. filtrationfiltered
  5. customThe filtrate was evaporated to dryness
  6. customthe 5 g of oil residue were chromatographed over silica gel
  7. washElution with a 7-3 cyclohexane-ethyl acetate mixture

Quellen und Nachweise

ORD-Eintrag
ord-39bca2a4c881429683fc3f1a46ac871e
Quelldatensatz
uspto-grants-1984_02
Patentnummer
US04431576

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