Imidazole → (-)-(1R,2S)-2-phenyl-1-cyclohexyl triisopropylsilyloxyacetate

HRID 2301447

Reaktionsgleichung

Reaktionsgleichung von HRID 2301447
C([O:8][CH2:9][C:10](Cl)=[O:11])C1C=CC=CC=1.[C:13]1([C@@H:19]2[CH2:24][CH2:23][CH2:22][CH2:21][C@H:20]2[OH:25])[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[CH:26]([Si:29](Cl)([CH:33]([CH3:35])[CH3:34])[CH:30]([CH3:32])[CH3:31])([CH3:28])[CH3:27].N1C=CN=C1>CN(C)C=O.CCCCC>[OH:11][CH2:10][C:9]([O:25][C@@H:20]1[CH2:21][CH2:22][CH2:23][CH2:24][C@H:19]1[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:8].[CH:26]([Si:29]([CH:33]([CH3:35])[CH3:34])([CH:30]([CH3:32])[CH3:31])[O:8][CH2:9][C:10]([O:25][C@@H:20]1[CH2:21][CH2:22][CH2:23][CH2:24][C@H:19]1[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:11])([CH3:28])[CH3:27]

Komponenten

8

Edukt 4

HCID 795ImidazoleHCID 102793rel-(1R,2S)-2-PhenylcyclohexanolHCID 139400Triisopropylsilyl chlorideHCID 177085Benzyloxyacetyl chloride

Produkt 2

HCID 10000489(-)-(1R,2S)-2-phenyl-1-cyclohexyl triisopropylsilyloxyacetateAusbeute 95 %HCID 10059921(-)-(1R,2S)-2-phenyl-1-cyclohexyl hydroxyacetate

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 6228DimethylformamideLösungsmittelHCID 8003PentaneLösungsmittel

Versuchsvorschrift

A solution of (−)-(1R,2S)-2-phenyl-1-cyclohexyl hydroxyacetate (851 mg, 3.63 mmol) was prepared through esterification of benzyloxyacetyl chloride with (−)-(1R,2S)-2-phenyl-1-cyclohexanol followed by hydrogenolysis. Then, triisopropylsilyl chloride (840 mg, 4.36 mmol) and imidazole (618 mg, 9.08 mmol) in dimethylformamide (DMF) (1.7 mL) was added and stirred at room temperature for 12-20 hours. The mixture was poured into pentane (25 mL), and washed with water and brine. The combined organic layers were dried over anhydrous MgSO4 and concentrated in vacuo. The crude product was subjected to a purification on a short silica gel column using hexane/chloroform (3/1) as the eluant to give pure (−)-(1R,2S)-2-phenyl-1-cyclohexyl triisopropylsilyloxyacetate (1.35 g, 95% yield) as a colorless oil: [α]D20-17.1° © 3.15, CHCl3); IR (neat) 1759, 1730 (nCO) cm−1, 1H NMR (CDCl3) δ 0.93-0.99 (m, 21H), 1.30-1.62 (m, 4H), 1.72-2.0 (m, 3H), 2.10-2.19 (m, 1H), 2.66 (dt, J=11.5, 4.0 Hz, 1H), 3.90 (d, J=16.6 Hz, 1H), 4.07 (d, J=16.6 Hz, 1H), 5.07 (dt, J=10.6, 4.0 Hz, 1H), 7.16-7.30 (m, 5H). Anal. Calcd for C23H38O3Si: C, 70.72; H, 9.81. Found: C, 70.79; H, 9.85.

Aufarbeitung

  1. washwashed with water and brine
  2. dry with materialThe combined organic layers were dried over anhydrous MgSO4
  3. concentrationconcentrated in vacuo
  4. customThe crude product was subjected to a purification on a short silica gel column

Quellen und Nachweise

ORD-Eintrag
ord-d316f77f7ee04fc0b2e062bfeecc3f03
Quelldatensatz
uspto-grants-2002_12
Patentnummer
US06500858B2

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