Gamma-Butyrolactone → 3-Benzyloxolan-2-one

HRID 2242782Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2242782
C(NC(C)C)(C)C.C([Li])CCC.[C:13]1(=[O:18])[O:17][CH2:16][CH2:15][CH2:14]1.[CH2:19](Br)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1>C1COCC1>[CH2:19]([CH:14]1[CH2:15][CH2:16][O:17][C:13]1=[O:18])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Komponenten

6

Edukt 4

HCID 7302Gamma-ButyrolactoneHCID 7498Benzyl BromideHCID 7912DiisopropylamineHCID 178418339Butyllithium

Produkt 1

HCID 5627583-Benzyloxolan-2-oneAusbeute 34 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Reaktionsbedingungen

Temperatur
-70 °C

Versuchsvorschrift

A solution of diisopropylamine (63.0 mL) in THF was treated dropwise with butyl lithium (268 mL of 1.6M solution in hexanes) at −10° C. Upon completion of the addition, the reaction mixture was cooled to −70° C. and then treated dropwise with γ-butyrolactone (33.0 mL) keeping the speed of the addition at such a rate that the temperature of the mixture remained below −60° C. After stirring for additional 30 min at −70° C., the mixture was treated dropwise with benzyl bromide (51.0 mL) again keeping the speed of the addition at such a rate that the temperature of the mixture remained below −60° C. After completion of the addition, the stirring of the reaction mixture was continued at −70° C. for 2 h. Then the mixture was warmed-up to 0° C. and quenched by addition of a small amount of water. The solvents were removed in vacuum and the residue was redissolved in dichloromethane, washed with 10% aqueous hydrochloric acid, then with water, dried over magnesium sulfate, filtered, concentrated on a rotary evaporator and distilled in vacuum to give 26.0 g (34%) of the title compound.

Aufarbeitung

  1. additionUpon completion of the addition
  2. additionthe speed of the addition at such a rate that the temperature of the mixture
  3. customremained below −60° C
  4. additionthe speed of the addition at such a rate that the temperature of the mixture
  5. customremained below −60° C
  6. additionAfter completion of the addition
  7. stirringthe stirring of the reaction mixture
  8. waitwas continued at −70° C. for 2 h
  9. temperatureThen the mixture was warmed-up to 0° C.
  10. customquenched by addition of a small amount of water
  11. customThe solvents were removed in vacuum
  12. dissolutionthe residue was redissolved in dichloromethane
  13. washwashed with 10% aqueous hydrochloric acid
  14. dry with materialwith water, dried over magnesium sulfate
  15. filtrationfiltered
  16. concentrationconcentrated on a rotary evaporator
  17. distillationdistilled in vacuum

Quellen und Nachweise

ORD-Eintrag
ord-2210e5462a9a47e7988e4d4738c262f7
Quelldatensatz
uspto-grants-2010_03
Patentnummer
US07674741B2

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