Bromine → 3-Bromo-2-hydroxy-cyclohex-1-enecarboxylic acid ethyl ester
反応式
[O:1]=[C:2]1[CH2:7][CH2:6][CH2:5][CH2:4][CH:3]1[C:8]([O:10][CH2:11][CH3:12])=[O:9].[Br:13]Br>C(OCC)C>[CH2:11]([O:10][C:8]([C:3]1[CH2:4][CH2:5][CH2:6][CH:7]([Br:13])[C:2]=1[OH:1])=[O:9])[CH3:12]参加物
4
反応条件
- 温度
- 0 °C
実験手順
Ethyl 2-oxocyclohexanecarboxylate (30 g, 176 mmol, 28 mL) was dissolved in diethyl ether (30 mL) and cooled to 0° C. under nitrogen. Bromine (28 g, 176 mmol, 9.0 mL) was added dropwise over 15 min and the reaction mixture was allowed to warm to RT over 90 min. The mixture was slowly poured into ice-cold saturated aqueous potassium carbonate (250 mL) and extracted with ethyl acetate (3×200 mL). The combined organic layers were dried over magnesium sulfate, filtered, concentrated in vacuo and dried on the vacuum line for 18 h to afford 41.4 g (94%) of 3-Bromo-2-hydroxy-1-enecarboxylic acid ethyl ester (4) as a yellow oil. The structure was confirmed by 13C NMR (75 MHz, CDCl3): δC 14.1, 17.7, 21.8, 32.0, 60.0, 60.8, 99.7, 166.3, and 172.8.