反应详情

64.3 g (180 mmol) of methyltriphenylphosphonium bromide was added while stirring under nitrogen to a solution of 19.1 g (170 mmol) of potassium tert-butylate in 350 ml of dry tetrahydrofuran and the mixture was heated to reflux. Then, a solution of 22.8 g (150 mmol) of spiro[2.7]decan-4-one in 50 ml of dry tetrahydrofuran was added dropwise to the boiling reaction mixture. The mixture was heated under reflux for a further 2 hours. After cooling, the reaction mixture was poured into 11 of tert-butyl methyl ether/water (1:1). The organic phase was separated and the aqueous phase was extracted twice with 500 ml of tert-butyl methyl ether. The organic extracts were combined, dried over sodium sulfate and concentrated on a rotary evaporator. After flash chromatography (n-pentane, Rf=0.97) on silica gel, there was obtained 17.1 g (76%) of 4-methylenespiro[2.7]decane (V, n=2) as a colorless liquid with the following properties:

1. temperaturethe mixture was heated to reflux
2. temperatureThe mixture was heated
3. temperatureunder reflux for a further 2 hours
4. temperatureAfter cooling
5. customThe organic phase was separated
6. extractionthe aqueous phase was extracted twice with 500 ml of tert-butyl methyl ether
7. dry with materialdried over sodium sulfate
8. concentrationconcentrated on a rotary evaporator