Ethyl levulinate → Ethyl 3-bromo-4-oxopentanoate

Participants

Reaction Steps

To a solution of ethyl 4-oxopentanoate (4.92 mL, 34.7 mmol) in Et2O (180 mL) at about 0° C. was added bromine (1.8 mL, 34.7 mmol) in Et2O (10 mL) and the reaction was stirred for about 3 h. To the reaction mixture was added saturated aqueous sodium thiosulfate (50 mL) and stirred for about 10 min. The reaction was warmed to ambient temperature. The organic layer was separated and the aqueous layer was back extracted with Et2O (30 mL). The combined organic layers were washed with water (20 mL), dried over MgSO4, filtered and concentrated under reduced pressure. The resulting oil was purified by column chromatography (SiO2, EtOAc/heptane 100:0 to 0:20) to afford ethyl 3-bromo-4-oxopentanoate (3.29 g, 14.6 mmol, 43%). 1H NMR (CDCl3) δ 4.67-4.33 (m, 1H), 4.15 (q, J=7.1 Hz, 2H), 3.29-3.22 (m, 1H), 2.90-2.86 (m, 1H), 2.42 (s, 3H), 1.26 (t, J=7.1 Hz, 3H).

Provenance & Evidence