Ethyl levulinate → Methyl 5-bromo-4-oxopentanoate
Reaktionsgleichung
[Br:1]Br.[O:3]=[C:4]([CH3:12])[CH2:5][CH2:6][C:7]([O:9][CH2:10]C)=[O:8]>CO>[Br:1][CH2:12][C:4](=[O:3])[CH2:5][CH2:6][C:7]([O:9][CH3:10])=[O:8]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A solution of bromine (27.71 g, 173.4 mmol) in methanol (40 mL) was added dropwise to a solution of ethyl 4-oxopentanoate (25.0 g, 173.4 mmol) in methanol (200 mL) at room temperature over a period of 30 minute, and the reaction mixture was stirred overnight. The reaction mixture was concentrated, and the residue was partitioned between 3:1 ether:ethyl acetate and water, washed with saturated sodium bicarbonate, water, brine, dried, and concentrated to afford 17 g of a crude clear oil. The oil was purified by MPLC (Biotage) eluting with 8:1 hexane ethyl acetate to afford methyl 5-bromo-4-oxopentanoate (10.65 g, 29.38% yield) as a clear oil. 1H NMR (CDCl3) δ 3.96 (s, 2H), 3.69 (s, 3H), 2.96 (t, 2H), 2.66 (t, 2H).