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 1387601

Reaktionsgleichung

Reaktionsgleichung von HRID 1387601
[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

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 1 N 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) δ1.05 (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 1 N 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-ec6ff8895c67420991db477d2e566693
Quelldatensatz
uspto-grants-2001_07
Patentnummer
US06268393B1

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