Sulfuric Acid → 2-Methoxymethyl-2,6,6-trimethylpyran-3,5-dione

HRID 1191581Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1191581
C(OC([CH:6]1[C:11](=[O:12])[C:10]([CH3:14])([CH3:13])[O:9][C:8]([CH2:16][O:17][CH3:18])([CH3:15])[C:7]1=[O:19])=O)C.S(=O)(=O)(O)O>O1CCOCC1.[Cl-].[Na+].O>[CH3:18][O:17][CH2:16][C:8]1([CH3:15])[C:7](=[O:19])[CH2:6][C:11](=[O:12])[C:10]([CH3:14])([CH3:13])[O:9]1

Komponenten

5

Edukt 2

HCID 1118Sulfuric AcidHCID 684865432-Methoxymethyl-2,6,6-trimethyl-3,5-dioxotetrahydropyran-4-carboxylic acid ethyl ester

Produkt 1

HCID 684880922-Methoxymethyl-2,6,6-trimethylpyran-3,5-dioneAusbeute 16,2 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 312751,4-DioxaneLösungsmittelHCID 57417360Sodium chloride; waterLösungsmittel

Reaktionsbedingungen

Temperatur
110 °C

Versuchsvorschrift

To a solution of 2-methoxymethyl-2,6,6-trimethyl-3,5-dioxotetrahydropyran-4-carboxylic acid ethyl ester (2.11 g, 7.72 mmol) in dioxane (2.5 ml) is added 20% aqueous sulfuric acid (2.5 ml) and the mixture is heated at 110° C. for 2.5 hours. The mixture is cooled to room temperature, diluted with saturated brine and extracted with dichloromethane. The crude material is extracted into aqueous sodium hydroxide, the aqueous phase washed with dichloromethane, then acidified with concentrated hydrochloric acid and extracted into dichloromethane (2×15 ml). The organic phase is concentrated in vacuo to give a crude oil which is purified by flash column chromatography on silica gel (isohexane/diethyl ether 7.5:1.5 ratio) to afford 2-methoxymethyl-2,6,6-trimethylpyran-3,5-dione (0.250 g) as a pink solid.

Aufarbeitung

  1. temperatureThe mixture is cooled to room temperature
  2. extractionextracted with dichloromethane
  3. extractionThe crude material is extracted into aqueous sodium hydroxide
  4. washthe aqueous phase washed with dichloromethane
  5. extractionextracted into dichloromethane (2×15 ml)
  6. concentrationThe organic phase is concentrated in vacuo
  7. customto give a crude oil which
  8. customis purified by flash column chromatography on silica gel (isohexane/diethyl ether 7.5:1.5 ratio)

Quellen und Nachweise

ORD-Eintrag
ord-fdd6106183194d6e8ca43e4f1060451d
Quelldatensatz
uspto-grants-2014_03
Patentnummer
US08680012B2

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