4,4-Dimethoxy-2-methylbutan-2-ol → 5-Hydroxy-2,2-dimethyl-6-propionyl-10-propyl-2H,8H-pyrano[2,3-f]chromen-8-one

HRID 342810

Reaktionsgleichung

Reaktionsgleichung von HRID 342810
[OH:1][C:2]1[CH:11]=[C:10]([OH:12])[C:9]([C:13](=[O:16])[CH2:14][CH3:15])=[C:8]2[C:3]=1[C:4]([CH2:18][CH2:19][CH3:20])=[CH:5][C:6](=[O:17])[O:7]2.CO[CH:23](OC)[CH2:24][C:25]([CH3:28])(O)[CH3:26]>N1C=CC=CC=1>[CH3:26][C:25]1([CH3:28])[O:1][C:2]2[C:3]3[C:4]([CH2:18][CH2:19][CH3:20])=[CH:5][C:6](=[O:17])[O:7][C:8]=3[C:9]([C:13](=[O:16])[CH2:14][CH3:15])=[C:10]([OH:12])[C:11]=2[CH:23]=[CH:24]1

Komponenten

4

Edukt 2

HCID 44399804,4-Dimethoxy-2-methylbutan-2-olHCID 54948785,7-Dihydroxy-8-propionyl-4-propyl-2H-chromen-2-one

Produkt 1

HCID 54948815-Hydroxy-2,2-dimethyl-6-propionyl-10-propyl-2H,8H-pyrano[2,3-f]chromen-8-oneAusbeute 79,1 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 1049PyridineLösungsmittel

Versuchsvorschrift

A mixture of 3 (2.60 g, 9.42 mmol) and 4,4-dimethoxy-2-methylbutan-2-ol (5.54 g, 37.7 mmol) were dissolved in anhydrous pyridine (6.5 mL). The mixture was refluxed under nitrogen for three days. After removal of the solvent in vacuo, the residue was dissolved in ethyl acetate. The ethyl acetate was washed several times with 1N HCl and brine. It was then dried over Na2SO4. The crude product obtained by evaporation in vacuo was purified by silica gel column chromatography, eluting with 25% ethyl acetate/hexane to afford 2.55 g of 4 in 78.6% yield, mp 96°-98° C. 1H-NMR (CDCl3) δ 1.05 (3H, t, J=7.3 Hz, CH3); 1.22 (3H, t, J=7.5 Hz, CH3); 1.53 (6H, s, 2 CH3); 1.75 (2H, m, CH2); 2.92 (2H, t, J=7.1 Hz, CH2); 3.35 (2H, q, J=7.1 Hz, CH2); 5.56 (1H, d, J=10.0 Hz, H3); 5.98 (1H, s, H9); 6.72 (1H, d, J=10.0 Hz, H4); MS (EI): 343 (5.7, M+1); 342 (22.5, M+); 327 (100, M--CH3); IR (KBr): 1728 (vs. C=O) cm-1 ; Anal. calcd. for C20H22O5 : C, 70.16; H, 6.48; Found: C, 70.45; H, 6.92.

Aufarbeitung

  1. temperatureThe mixture was refluxed under nitrogen for three days
  2. customAfter removal of the solvent in vacuo
  3. dissolutionthe residue was dissolved in ethyl acetate
  4. washThe ethyl acetate was washed several times with 1N HCl and brine
  5. dry with materialIt was then dried over Na2SO4
  6. customThe crude product obtained by evaporation in vacuo
  7. customwas purified by silica gel column chromatography
  8. washeluting with 25% ethyl acetate/hexane

Quellen und Nachweise

ORD-Eintrag
ord-b8de4dea31cc4e778948e0bdd7030722
Quelldatensatz
uspto-grants-1999_01
Patentnummer
US05859050

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