反应详情

1,4-Dioxaspiro[4.5]decan-8-one (40 g) and diethyl aminomethylenemalonate (47.94 g) are dissolved in 500 ml of toluene. p-Toluenesulfonic acid monohydrate (2.44 g) and 100 ml of toluene are then added and the mixture is refluxed for 3 days collecting water in a Dean-Stark trap. The resulting mixture is decanted and solvent is removed to leave on oil. This oil is flash chromatographed on 750 g silica gel using 9:1 CH2Cl2, EtOAc as eluant to yield diethyl N-(1,4-dioxaspiro[4.5]decen-8-yl)aminomethylenemalonate as an oil.

1. temperaturethe mixture is refluxed for 3 days
2. customcollecting water in a Dean-Stark trap
3. customThe resulting mixture is decanted
4. customsolvent is removed
5. customto leave on oil
6. customchromatographed on 750 g silica gel using 9:1 CH2Cl2, EtOAc as eluant