Sodium Hydroxide → cis-4-Tert-butyloxy-cyclopent-2-enol

HRID 2393890

Reaktionsgleichung

Reaktionsgleichung von HRID 2393890
[H-].[Al+3].[Li+].[H-].[H-].[H-].[I-].[Li+].[C:9]([O:13][CH:14]1[CH2:18][C:17](=[O:19])[CH:16]=[CH:15]1)([CH3:12])([CH3:11])[CH3:10].[OH-].[Na+]>C1(C)C=CC=CC=1.COC(C)(C)C>[C:9]([O:13][C@@H:14]1[CH2:18][C@H:17]([OH:19])[CH:16]=[CH:15]1)([CH3:12])([CH3:10])[CH3:11]

Komponenten

7

Edukt 4

HCID 14798Sodium HydroxideHCID 66321Lithium iodideHCID 110625964-Tert-butoxy-cyclopent-2-enoneHCID 21226445Aluminium lithium hydride

Produkt 1

HCID 11789450cis-4-Tert-butyloxy-cyclopent-2-enolAusbeute 42 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 1140TolueneLösungsmittelHCID 15413tert-Butyl methyl etherLösungsmittel

Versuchsvorschrift

A slurry of lithium aluminum hydride (55 mg, 1.44 mmol), lithium iodide (1.65 g, 5.76 mmol), tert-butyl methyl ether (2 mL) and toluene (3 mL) is cooled to -15° C. The slurry is treated dropwise with 4-tert-butoxy-cyclopent-2-enone(430 mg, 2.79 mmol, dissolved in 1 mL of toluene) over 5 minutes. The reaction mixture is stirred at -20° C. to -12° C. for 2 hours and then allowed to warm to room temperature and is stirred for 30 minutes. The reaction mixture is then treated sequentially with sodium hydroxide (1N, 1 mL), then tert-butyl methyl ether (10 mL) and filtered. The phases of the filtrate are separated and the aqueous phase is extracted with tert-butyl methyl ether (15 mL). The organic extracts and organic phase is combined, dried over magnesium sulfate, filtered and concentrated under vacuum. The residue is purified by chromatography (silica gel, 30 g, 33% ethyl acetate/hexane) to provide the title compound (183 mg, 42%) as a yellow oil, cis/trans/l-2+l-4 addition, 87/9.8/3.2; 1H NMR (CDCl3) δ 5.9 (m, 1 H), 5.8 (m, 1 H), 4.6 (m, 1 H), 4.5 (m, 1 H), 2.7 (m, 1 H), 2.0 (d,1 H, J=9.6 Hz), 1.5 (d appt, 1 H, J=4.5, 14 Hz), 1.2 (s, 9 H); 13 C NMR (CDCl3) δ 136.6, 136, 75.5, 74.4, 74, 44.6, 28.7; νmax 3395, 2974, 2938, 2907, 2878, 1389, 1364, 1117, 1169, 1022 cm-1 ; MS (CI) m/e (% relative intensity) 157 (M+H+ --H2 O), 57, 83 (100).

Aufarbeitung

  1. stirringis stirred for 30 minutes
  2. filtrationtert-butyl methyl ether (10 mL) and filtered
  3. customThe phases of the filtrate are separated
  4. extractionthe aqueous phase is extracted with tert-butyl methyl ether (15 mL)
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated under vacuum
  8. customThe residue is purified by chromatography (silica gel, 30 g, 33% ethyl acetate/hexane)
  9. customto provide

Quellen und Nachweise

ORD-Eintrag
ord-f9831cc802f24b60a407981754dd67f0
Quelldatensatz
uspto-grants-1998_09
Patentnummer
US05808112

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