Tetrahydrofuran → HCID 59201437, Verbindung

HRID 451878Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 451878
C1(OC(=O)[CH2:9][CH2:10][C@@H:11]([CH2:27][O:28]S(C2C=CC(C)=CC=2)(=O)=O)[CH2:12][C@H:13]2[CH2:17][O:16][C:15]([CH3:19])([CH3:18])[N:14]2[C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])CCCCC1.C[Mg]Br.[CH2:43]1[CH2:47]OC[CH2:44]1>>[CH3:44][C:43]1([CH3:47])[O:28][CH2:27][C@@H:11]([CH2:12][C@H:13]2[CH2:17][O:16][C:15]([CH3:19])([CH3:18])[N:14]2[C:20]([O:22][C:23]([CH3:25])([CH3:26])[CH3:24])=[O:21])[CH2:10][CH2:9]1

Komponenten

5

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

The (S)-tert-butyl 4-((R)-5-(cyclohexyloxy)-5-oxo-2-(tosyloxymethyl)pentyl)-2,2-dimethyloxazolidine-3-carboxylate (309 mg, 0.545 mmol, 1.0 equiv) was dissolved in 17 mL of THF and the solution cooled to 0° C. Methylmagnesiumbromide (3.0 M in THF, 1.64 mL, 3.0 equiv) was added via syringe. LC/MS analysis showed ca 15% conversion to the mono-tosylate. An additional 0.55 mL of MeMgBr solution was added and the mixture warmed to ambient and stirred overnight. LC/MS analysis showed complete conversion to the mono-tosylate. The mixture was heated to reflux for 24 hr. After this time, complete conversion to the cyclised product was observed. The mixture was cooled to ambient and quenched with water. The layers were separated and the organic layer washed with brine, dried over Na2SO4, filtered and evaporated. The pyran derivative was purified by flash chromatography on silica, (12 g), eluting with 0-41% EtOAc in hexanes. This afforded 138 g (78% yield) of (S)-tert-butyl 4-(((R)-6,6-dimethyl-tetrahydro-2H-pyran-3-yl)methyl)-2,2-dimethyloxazolidine-3-carboxylate as a clear syrup. MS ESI +ve m/z 350 (M+Na).

Aufarbeitung

  1. temperaturethe mixture warmed
  2. temperatureThe mixture was heated
  3. temperatureto reflux for 24 hr
  4. temperatureThe mixture was cooled to ambient and
  5. customquenched with water
  6. customThe layers were separated
  7. washthe organic layer washed with brine
  8. dry with materialdried over Na2SO4
  9. filtrationfiltered
  10. customevaporated
  11. customThe pyran derivative was purified by flash chromatography on silica, (12 g)
  12. washeluting with 0-41% EtOAc in hexanes

Quellen und Nachweise

ORD-Eintrag
ord-d2181287a45f43b0b8b1827a9bc22f86
Quelldatensatz
uspto-grants-2013_07
Patentnummer
US08487108B2

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