Boron tribromide → HCID 21079760, Verbindung
Reaktionsgleichung
[CH2:1]([C:3]1[CH:8]=[CH:7][C:6]([CH2:9][C:10]([O:12][CH2:13][CH3:14])=[O:11])=[CH:5][C:4]=1[O:15]C)[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[OH:15][C:4]1[CH:5]=[C:6]([CH2:9][C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:7]=[CH:8][C:3]=1[CH2:1][CH3:2]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A solution of ethyl 4-ethyl-3-methoxyphenylacetate (4f; 3.0 g; 13.50 mmol) and CH2Cl2 (80 mL) cooled to −78° C. and a solution of BBr3 (5.10 mL; 53.94 mmol; 1.0 M in CH2Cl2) over 30 min. After 1 h at −78° C. the reaction was allowed to warm to rt and stirred for 12 h. The reaction was cooled in an ice-water bath and the reaction quenched with 20 mL of water. The aqueous phase was extracted with CH2Cl2:EtOAc (4:1 v/v), dried (Na2SO4), filtered and evaporated. The crude product was purified by silica gel chromatography and eluted with a CH2Cl2:EtOAc gradient (100:1→100:4) to yield 5b (2.0 g; 71%): m.s. 209.2 (M+H)+.