Acetic Acid → 6-Benzyloxymethyl-2-methyl-5,6-dihydro-4H-pyran-4-one

HRID 21566

Reaktionsgleichung

Reaktionsgleichung von HRID 21566
[CH2:1]([O:8][CH2:9][CH:10]=[O:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Mg+2].[Br-].[Br-].C[Si](C)(C)O[CH:18]=[CH:19][C:20]([O:22][Si](C)(C)C)=[CH2:21].[CH3:29]C(O)=O>C1COCC1>[CH2:1]([O:8][CH2:9][CH:10]1[O:11][C:18]([CH3:29])=[CH:19][C:20](=[O:22])[CH2:21]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Komponenten

6

Edukt 4

HCID 176Acetic AcidHCID 82241Magnesium BromideHCID 108989(Phenylmethoxy)acetaldehydeHCID 544944351,3-Bis (trimethylsilyloxy)butadiene

Produkt 1

HCID 199330426-Benzyloxymethyl-2-methyl-5,6-dihydro-4H-pyran-4-oneAusbeute 60 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

A solution of 10.4 g of the aldehyde from Step 1 in 250 ml of THF was cooled to 0° C. and 1.0 eq of freshly prepared MgBr2 was added dropwise. The mixture was warmed to r.t. and 40.6 g of 1,3-bis(trimethylsilyloxy)-1,3-butadiene (Emde, et al., Synthesis p. 6 (1982)) was added. After 3.0 h, 50% aqueous HOAc was added and the mixture was stirred 10 min and then extracted with Et2O (2×). After the ether was evaporated, the resultant oil was taken back up in 300 ml of CH2Cl2 and 12 ml of TFA. After 3 hours, the solution was washed with H2O, saturated NaHCO3, and brine and finally dried over MgSO4. After flash chromatography, 9.5 g (60%) of the title compound was obtained.

Aufarbeitung

  1. extractionextracted with Et2O (2×)
  2. customAfter the ether was evaporated
  3. waitAfter 3 hours
  4. washthe solution was washed with H2O, saturated NaHCO3, and brine
  5. dry with materialfinally dried over MgSO4

Quellen und Nachweise

ORD-Eintrag
ord-4f1710eda3b94485a32923fad0a20b4b
Quelldatensatz
uspto-grants-1995_06
Patentnummer
US05424320

Verknüpfte Notizen

Wird geladen…