tert-Butyl methyl ether → (+/-)-cis-4-Trityloxy-2-cyclopentenol

HRID 2564

Reaktionsgleichung

Reaktionsgleichung von HRID 2564
[C:1]([O:20][CH:21]1[CH2:25][C:24](=[O:26])[CH:23]=[CH:22]1)([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[H-].[Al+3].[Li+].[H-].[H-].[H-].[I-].[Li+].COC(C)(C)C>C1(C)C=CC=CC=1>[C:1]([O:20][C@@H:21]1[CH2:25][C@H:24]([OH:26])[CH:23]=[CH:22]1)([C:8]1[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1)([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Komponenten

6

Edukt 4

HCID 15413tert-Butyl methyl etherHCID 66321Lithium iodideHCID 109914404-Trityloxy-2-cyclopentenoneHCID 21226445Aluminium lithium hydride

Produkt 1

HCID 10980801(+/-)-cis-4-Trityloxy-2-cyclopentenolAusbeute 95 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 1140TolueneLösungsmittel

Reaktionsbedingungen

Temperatur
-20 °C

Versuchsvorschrift

A slurry of 4-trityloxy-2-cyclopentenone (1.03 g, 3.03 mmol, prepared in example 27) in toluene (8 mL) is cooled to -20° C. and treated sequentially with lithium aluminum hydride (76 mg, 2.0 mL), lithium iodide (1.06 g, 7.9 mmol) and dropwise with tert-butyl methyl ether (2 mL, over 5 minutes). The reaction is stirred for 1 hour at -20° C., warmed to 0° C. over 30 minutes, and stirred at 0° C. to 15° C. for 4 hours. The reaction is quenched by slow addition of 1N NaOH (2 mL) and then the reaction is filtered. The solids are washed with tert-butyl methyl ether and the phases of the filtrate are separated. The organic phase is dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue is purified by column chromatography (silica gel, 20% ethyl acetate/hexane) to provide the title compound as a white foam (980 mg, 95%). 1H NMR (CDCl3) δ7.5 (m, 6H), 7.3 (m, 9H), 5.79 (d, 1H), 5.14 (d, 1H), 4.5 (m, 1H), 4.4 (m, 1H), 2.2 (m, 1H), 1.42 (d, 1H); 13C NMR (CDCl3) δ145.1, 136.2, 135.9, 129.0, 128.1, 127.3, 87.7, 77.4, 74.9, 43.2; IR (KBr) νmax 3422, 3057, 1491, 1364, 1084, 1065, 1024 cm-1.

Aufarbeitung

  1. temperaturewarmed to 0° C. over 30 minutes
  2. stirringstirred at 0° C. to 15° C. for 4 hours
  3. customThe reaction is quenched by slow addition of 1N NaOH (2 mL)
  4. filtrationthe reaction is filtered
  5. washThe solids are washed with tert-butyl methyl ether
  6. customthe phases of the filtrate are separated
  7. dry with materialThe organic phase is dried over anhydrous magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated under vacuum
  10. customThe residue is purified by column chromatography (silica gel, 20% ethyl acetate/hexane)

Quellen und Nachweise

ORD-Eintrag
ord-802e8dff62b74fa49096ebf9f90abcb7
Quelldatensatz
uspto-grants-1998_03
Patentnummer
US05728899

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