反应详情

温度

-78 °C

Diisopropylamine (48.6 g, 480 mmol) is dissolved in 350 ml of tetrahydrofuran. At -40° C. there are added dropwise thereto 275 ml (440 mmol) of 1.6 molar butyl-lithium solution in hexane. The mixture is then cooled to -78° C. and 44.02 g (200 mmol) of 3-benzoyloxy-2,4-pentane-dione in 50 ml of tetrahydrofuran are added dropwise thereto within 30 minutes. Subsequently, 22.20 g (300 mmol) of ethyl formate are adde dropwise thereto at -78° C. within 30 minutes and the mixture is stirred for 2 hours. The reaction mixture is poured into 600 ml of 1N hydrochloric acid, saturated with sodium chloride and extracted three times with 500 ml of ethyl acetate each time. The combined organic phases are dried over magnesium sulphate, concentrated on a rotary evaporator and give 54.30 g of 4-benzoyloxy-1-hydroxy-1-hexene-3,5-dione.

1. additionAt -40° C. there are added dropwise
2. waitat -78° C. within 30 minutes
3. extractionextracted three times with 500 ml of ethyl acetate each time
4. dry with materialThe combined organic phases are dried over magnesium sulphate
5. concentrationconcentrated on a rotary evaporator