反应详情

温度

-78 °C

A solution of 1,4-cyclohexanedione mono-ethylene acetal (20 g, 28 mmol) in THF (360 ml) is added dropwise under nitrogen to a solution, cooled to −78° C., of 1M lithium diisopropylamide in THF (150 mmol, 150 ml), and the mixture is then allowed to return to room temperature. After stirring for 1 hour, the mixture is cooled to −78° C. and 35.2 g (141 mmol) of 2-bromobenzyl bromide are added dropwise. After stirring for 30 minutes at −78° C., the temperature of the mixture is returned to 0° C. The mixture is stirred for 3 hours at 0° C. and then hydrolysed and extracted with ether. The organic phase is washed with a saturated NaCl solution, dried over MgSO4 and concentrated in vacuo. The title compound is purified by flash chromatography over a column.

1. customto return to room temperature
2. stirringAfter stirring for 30 minutes at −78° C.
3. customis returned to 0° C
4. stirringThe mixture is stirred for 3 hours at 0° C.
5. extractionhydrolysed and extracted with ether
6. washThe organic phase is washed with a saturated NaCl solution
7. dry with materialdried over MgSO4
8. concentrationconcentrated in vacuo
9. customThe title compound is purified by flash chromatography over a column