Ethyl Acetate → benzyl (2S,3S)-3-hydroxy-2,3-dimethylpyrrolidine-1-carboxylate

HRID 1173585Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1173585
[Cl-].[Ce+3].[Cl-].[Cl-].C[Mg]Br.[CH2:8](OCC)C.[CH3:13][C@H:14]1[C:18](=[O:19])[CH2:17][CH2:16][N:15]1[C:20]([O:22][CH2:23][C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1)=[O:21].C(OCC)(=O)C>C1COCC1>[OH:19][C@@:18]1([CH3:8])[CH2:17][CH2:16][N:15]([C:20]([O:22][CH2:23][C:24]2[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=2)=[O:21])[C@H:14]1[CH3:13]

Komponenten

6

Edukt 4

HCID 8857Ethyl AcetateHCID 24636Cerium(III) chlorideHCID 59556933benzyl (2S)-2-methyl-3-oxopyrrolidine-1-carboxylateHCID 178467822HCID 178467822, Verbindung

Produkt 1

HCID 59557026benzyl (2S,3S)-3-hydroxy-2,3-dimethylpyrrolidine-1-carboxylateAusbeute 84 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

A suspension of cerium chloride (47 g) in THF (300 mL) was cooled to −78° C., methylmagnesium bromide-diethyl ether solution (56 mL, 3 mol/L) was added dropwise while adjusting the solution temperature to −70° C. or below. After the completion of the dropwise addition, the mixture was stirred at −78° C. for 30 min, a solution of benzyl(2S)-2-methyl-3-oxopyrrolidine-1-carboxylate (18 g) in THF (60 mL) was added dropwise while adjusting the solution temperature to −70° C. or below. The reaction mixture was warmed to 0° C. over 2 hr, ethyl acetate (1 L) was added, and insoluble materials were filtered off. The filtrate was partitioned with water, and the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=9/1→1/1) to give the title compound as a colorless oil (yield: 16.2 g, 84%).

Aufarbeitung

  1. customto −70° C. or below
  2. additionAfter the completion of the dropwise addition
  3. customto −70° C. or below
  4. temperatureThe reaction mixture was warmed to 0° C. over 2 hr
  5. filtrationinsoluble materials were filtered off
  6. customThe filtrate was partitioned with water
  7. washthe organic layer was washed with saturated brine
  8. dry with materialdried over anhydrous sodium sulfate
  9. concentrationconcentrated under reduced pressure
  10. customThe residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=9/1→1/1)

Quellen und Nachweise

ORD-Eintrag
ord-0b32a61df77c47d9915374284832dad3
Quelldatensatz
uspto-grants-2010_11
Patentnummer
US07834051B2

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