反应详情

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).

1. concentrationThe reaction mixture was concentrated
2. customthe residue was partitioned between 3:1 ether
3. washethyl acetate and water, washed with saturated sodium bicarbonate, water, brine
4. customdried
5. concentrationconcentrated
6. customto afford 17 g of a crude clear oil
7. customThe oil was purified by MPLC (Biotage)
8. washeluting with 8:1 hexane ethyl acetate