3,4-dihydro-2H-pyran → 4-(Tetrahydro-pyran-2-yloxy)-cyclopent-2-enone

HRID 2393887

Reaktionsgleichung

Reaktionsgleichung von HRID 2393887
[OH:1][CH:2]1[CH2:6][C:5](=[O:7])[CH:4]=[CH:3]1.[O:8]1[CH:13]=[CH:12][CH2:11][CH2:10][CH2:9]1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>O1CCCC1.C(OCC)(=O)C>[O:8]1[CH2:13][CH2:12][CH2:11][CH2:10][CH:9]1[O:7][CH:5]1[CH2:6][C:2](=[O:1])[CH:3]=[CH:4]1

Komponenten

6

Edukt 3

HCID 80803,4-dihydro-2H-pyranHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 41691604-Hydroxycyclopent-2-en-1-one

Produkt 1

HCID 128380104-(Tetrahydro-pyran-2-yloxy)-cyclopent-2-enoneAusbeute 76 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 8028TetrahydrofuranLösungsmittelHCID 8857Ethyl AcetateLösungsmittel

Versuchsvorschrift

A solution of 4-hydroxy-2-cyclopentenone (1.41 g, 14.4 mmol) in tetrahydrofuran (24 mL) is treated with 3,4-dihydro-2H-pyran (2 mL) and pyridinium p-toluenesulfonate (500 mg, PPTS). The reaction is stirred at room temperature for 18 hours. The reaction mixture is then diluted with ethyl acetate (25 mL) and washed with 50% saturated brine (2×30 mL). The organic layer is dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum. The resulting crude brown oil is purified by filtration through a plug of silica gel (25 g, 33% ethyl acetate/hexane) to provide the title compound as a yellow oil (2.00 g, 76%); 1H NMR (CDCl3) δ 7.46 (2×dd, 1 H, J=16.3, 5.7 Hz), 6.2 (m, 1H), 4.9 (m, 1 H), 4.80 (d appt, 1 H, J=23.8, 2.9 Hz), 3.9 (m, 1 H), 3.6 (m, 1 H), 2.73 (2×dd, 1 H, J=18.4, 6.2 Hz), 2.35 (2×d, 1 H, J=18.4 Hz), 1.8 (m, 1 H), 1.6 (m, 4 H); IR (neat) νmax 2944, 2870, 2855, 1723, 1348, 1202, 1182, 1152, 1128, 1078, 1032 cm-1 ; MS (CI) m/e (% relative intensity) 183 (M+H+, 28), 85(100).

Aufarbeitung

  1. washwashed with 50% saturated brine (2×30 mL)
  2. dry with materialThe organic layer is dried over anhydrous magnesium sulfate
  3. filtrationfiltered
  4. concentrationconcentrated under vacuum
  5. filtrationThe resulting crude brown oil is purified by filtration through a plug of silica gel (25 g, 33% ethyl acetate/hexane)

Quellen und Nachweise

ORD-Eintrag
ord-5282c08976cb47b79aaa6649e9f6a23a
Quelldatensatz
uspto-grants-1998_09
Patentnummer
US05808112

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