Acetoin → Tert-butyldimethylsilyloxybutan-2-ol

HRID 1587814Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1587814
[Si:1]([O:8][CH:9](C)[C:10](=[O:12])[CH3:11])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].O[CH:15](C)C(=O)C.[Si](Cl)(C(C)(C)C)(C)C.N1C=CN=C1.C(OC1C=C([Mg]Br)C=C(F)C=1)C1C=CC=CC=1.BrC1C=C(OCC2C=CC=CC=2)C=C(F)C=1.[Mg]>C(OCC)C.O1CCCC1>[Si:1]([O:8][CH2:9][CH:10]([OH:12])[CH2:11][CH3:15])([C:4]([CH3:5])([CH3:6])[CH3:7])([CH3:2])[CH3:3]

Komponenten

10

Edukt 7

HCID 179AcetoinHCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 5462224MagnesiumHCID 110418312-Butanone, 3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-HCID 112545161-(Benzyloxy)-3-bromo-5-fluorobenzeneHCID 178505958HCID 178505958, Verbindung

Produkt 1

HCID 21640814Tert-butyldimethylsilyloxybutan-2-olAusbeute 41 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 3283Diethyl EtherLösungsmittelHCID 8028TetrahydrofuranLösungsmittel3×

Versuchsvorschrift

A solution of 3-tert-butyldimethylsilyloxybutan-2-one (5.56 g; prepared by reacting 3-hydroxybutan-2-one with tert-butyldimethylsilyl chloride in diethyl ether and using imidazole as a suitable base) in tetrahydrofuran (5 ml) was added to a solution of 3-benzyloxy-5-fluorophenylmagnesium bromide [prepared by heating a mixture of benzyl 3-bromo-5-fluorophenyl ether (6.7 g), magnesium powder (0.58 g) and tetrahydrofuran (50 ml) to 40° C. for 1 hour] in tetrahydrofuran (50 ml) and the mixture was stirred at ambient temperature for 2.5 hours. The mixture was evaporated and the residue was partitioned between diethyl ether and water. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO4) and evaporated. The residue was purified by column chromatography using a 3:2 v/v mixture of petroleum ether (b.p. 40°-60° C.) and methylene chloride as eluent. There was thus obtained an erythro isomer, (2RS,3SR)-2-(3-benzyloxy-5-fluorophenyl)-3-(tert-butyldimethylsilyloxybutan-2-ol (3.8 g, 41%), as an oil; and a threo isomer, the corresponding (2RS,3RS)-isomer (1.73 g, 18%), as an oil.

Aufarbeitung

  1. customprepared
  2. customprepared
  3. temperatureby heating
  4. customThe mixture was evaporated
  5. customthe residue was partitioned between diethyl ether and water
  6. washThe organic phase was washed with a saturated aqueous sodium chloride solution
  7. dry with materialdried (MgSO4)
  8. customevaporated
  9. customThe residue was purified by column chromatography
  10. additiona 3:2 v/v mixture of petroleum ether (b.p. 40°-60° C.) and methylene chloride as eluent

Quellen und Nachweise

ORD-Eintrag
ord-6487f155c6fb4347a29dc2e7b88b2fb7
Quelldatensatz
uspto-grants-1993_06
Patentnummer
US05219881

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