反応 #95967

反応方程式

benzyltriphenylphosphonium bromide

n-butyllithium

cyclohexane-1,4-dione

→

4-benzylidenecyclohexanone

収率 120.0%

溶媒

THF

THF

pentane

反応条件

後処理

1. 1
   温度' heating
2. 2
   温度at reflux the mixture
3. 3
   温度to cool
4. 4
   洗浄was then washed in turn with water and brine
5. 5
   濃縮The organic layer was concentrated
6. 6
   その他the residue was chromatographed on 1 liter of silica gel
7. 7
   洗浄eluting with 20% ethyl acetate in Skellysolve® B

実験手順

To a mechanically stirred suspension of 15.24 g (0.035 mole) of benzyltriphenylphosphonium bromide in 150 ml of THF there was added first 22 ml of 1.61 N n-butyllithium in pentane and then 5.0 g (0.032 mole) of cyclohexane-1,4-dione, ethylene monoketal in 50 ml of THF. Following 5 hours' heating at reflux the mixture was allowed to cool and was then washed in turn with water and brine. The organic layer was concentrated, and the residue was chromatographed on 1 liter of silica gel, eluting with 20% ethyl acetate in Skellysolve® B, to afford 7.15 g (97%) of 4-benzylidenecyclohexanone, ethylene ketal as an oil, the nmr spectrum of which is in consonance with the structure.

出典