2-Methylcyclopentanone → 2-Methyl-1-phenylethynylcyclopentanol

HRID 1757687

Reaktionsgleichung

Reaktionsgleichung von HRID 1757687
[CH3:1][CH:2]1[CH2:6][CH2:5][CH2:4][C:3]1=[O:7].[Li+].[C-:9]#[C:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1>C1COCC1>[CH3:1][CH:2]1[CH2:6][CH2:5][CH2:4][C:3]1([C:9]#[C:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)[OH:7]

Komponenten

4

Edukt 2

HCID 142652-MethylcyclopentanoneHCID 3437284Lithium phenylacetylide

Produkt 1

HCID 108673482-Methyl-1-phenylethynylcyclopentanolAusbeute 60 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

2-Methylcyclopentanone (1.96 g, 19.9 mmol), dissolved in 10 mL of freshly distilled THF, was added dropwise via an additional funnel to an ice-bath cooled solution containing 25 mmol of lithium phenylacetylide (25 mL×1.0M) in 10 mL of THF. The reaction mixture during the addition was maintained at 0° C. and also kept under nitrogen purging. The reaction was maintained for an additional 2 hours at 0° C. and thenstirred at room temperature for 18 hour. The THF solution was quenched by ice water mixture containing excess amounts of NH4Cl. The aqueous solution was extracted by diethyl ether (2×75 mL). The ether layer was washed with water (3×50 mL) and dried with MgSO4. Accordingto GC analysis the conversion to the product was 80%. The product was isolated by means of silica gel column chromatography (40-140 mesh). The unreacted keetone was eluted as the first fraction with hexanes. The second fraction gave the product with diethyl ether as the eluant. After acomplete solvent evaporation under vacuum, a solid was obtained in 60% yield (2.37 g). The product was characterized by spectroscopy: 1H-NMR (CDCl3) δ61.14 (d, 3H), 1.43 (m, 1H), 1.80 (m, 2H), 2.13 (m, 4H), 7.31 (m, 3H), 7.44 (m, 2H); IR (nujol) 3300 (s), 1600 (m), 1450 (s), 1425 (m), 1400 (w), 1190 (m), 1070 (s), 1040 (s), 950 (m), 910 (m), 750 (s), 690 (s) cm-1 ; MS m/z (rel. int.) Isomer A, 200 (M+, 12), 185 (M-CH3, 23), 182 (16), 171 (100), 167 (14), 1676 (12), 165 (15), 157 (12), 155 (18), 153 (16), 152 (13), 143 (20), 142 (15), 141 (49), 139 (10), 129 (69), 128 (65), 127 (24), 115 (56), 91 (29), 101 (11), 77 (22); Isomer B, 200 (M+, 17), 157 (50), 144 (39), 143 (14), 130 (17), 129 (100),117 (14), 115 (38), 102 (19), 91 (17), 77 (18); HR mass: Calcd; 200.1201. Found; 200.1603.

Aufarbeitung

  1. additionwas added dropwise via an additional funnel to an ice-bath
  2. temperaturecooled solution
  3. additionThe reaction mixture during the addition
  4. temperatureThe reaction was maintained for an additional 2 hours at 0° C. and thenstirred at room temperature for 18 hour
  5. customThe THF solution was quenched by ice water mixture
  6. additioncontaining excess amounts of NH4Cl
  7. extractionThe aqueous solution was extracted by diethyl ether (2×75 mL)
  8. washThe ether layer was washed with water (3×50 mL)
  9. dry with materialdried with MgSO4
  10. customThe product was isolated by means of silica gel column chromatography (40-140 mesh)
  11. washThe unreacted keetone was eluted as the first fraction with hexanes
  12. customThe second fraction gave the product with diethyl ether as the eluant
  13. customAfter acomplete solvent evaporation under vacuum
  14. customa solid was obtained in 60% yield (2.37 g)

Quellen und Nachweise

ORD-Eintrag
ord-837290f9f0ef47298d6ed5155c4ff4f9
Quelldatensatz
uspto-grants-1995_08
Patentnummer
US05446203

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