p-Toluenesulfonic acid → 2-(5-Bromo-2-methoxyphenyl)-1,3-dioxane
Reaktionsgleichung
[Br:1][C:2]1[CH:9]=[C:6]([CH:7]=[O:8])[C:5]([O:10][CH3:11])=[CH:4][CH:3]=1.[CH2:12](O)[CH2:13][CH2:14][OH:15].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([O:10][CH3:11])=[C:6]([CH:7]2[O:15][CH2:14][CH2:13][CH2:12][O:8]2)[CH:9]=1Komponenten
5
Edukt 3
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A solution of 5-bromo-o-anisaldehyde (25 g, 116 mmol), 1,3-propandiol (9 mL, 125 mmol), p-toluenesulphonic acid (0.1 g) in toluene (150 mL) was heated and water was azeotropically removed using a Dean-Stark water-separator. After 18 hours, the solution was washed with 5% Na2CO3 (100 ml), dried (K2CO3) and the solvent was removed under reduced pressure. The acetal was purified by vacuumdistillation and isolated as clear oil: