5-hydroxy-4H-chromen-4-one → 3,4-Dihydro-2H-1-benzopyran-5-ol
Reaktionsgleichung
[OH:1][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[C:4](=O)[CH:5]=[CH:6][O:7]2>[Pd].CCO.C1COCC1>[O:7]1[C:8]2[CH:9]=[CH:10][CH:11]=[C:2]([OH:1])[C:3]=2[CH2:4][CH2:5][CH2:6]1Komponenten
4
Edukt 1
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 2
Versuchsvorschrift
To a solution of 5-hydroxy-chromen-4-one (J. Het. Chem, 13, 1976, 211) (2.5 g, 15.4 mmol) and 1 mL HCl(c) in 75 mL de-gassed EtOH/THF (3:1) was added 0.5 g 10% Pd/C. The reaction mixture was stirred at room temperature for 20 h under an atmosphere of 1 atm H2(g). The Pd/C was then filtered off, the filtrate collected and concentrated in vacuo to give 2.1 g (91%) of the title compound pure enough for subsequent use. 400 MHz 1H NMR (DMSO-d6) δ 9.27 (s, 1H), 6.76 (t, 1H, J=8.1 Hz), 6.26 (d, 1H, J=8.1 Hz), 6.12 (d, 1H, J=8.1 Hz), 3.98 (t, 2H, J=5.0 Hz), 2.46 (m, 2H), 1.80 (m, 2H).