Reaktion #682426

Reaktionsgleichung

glycerol

benzaldehyde

water

→

2-phenyl-1,3-dioxan-5-ol

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe resulting mixture was heated
2. 2
   SonstigeWhen the separation of water
3. 3
   Einengenthe solvent was concentrated under reduced pressure
4. 4
   Sonstigeto give a white solid which
5. 5
   Sonstigewas recrystallized from ether/petroleum ether
6. 6
   Sonstigerecrystallization from the same solvent

Vorschrift

Concentrated sulfuric acid (3 drops) was added to a mixture of glycerol (55.1 g, 0.60 mmol) and benzaldehyde (50.0 g, 0.47 mmol) in toluene (69 mL) and the resulting mixture was heated to reflux in a Dean-Stark water separator under nitrogen. When the separation of water was complete, the solvent was concentrated under reduced pressure to give a white solid which was recrystallized from ether/petroleum ether. Repeated recrystallization from the same solvent gave pure 2-phenyl-1,3-dioxan-5-ol. 1H NMR (300 MHz, CDCl3) δ 7.51-7.48 (m, 2H), 7.41-7.37 (m, 3H), 5.55 (s, 1H), 4.21-4.17 (m, 2H), 4.14-4.10 (m, 2H), 3.63 (s, 1H), 2.78 (bs, 1H).

Quelle