反応 #674298

反応方程式

potassium t-butoxide

tert-butyl 4-oxopiperidine-1-carboxylate

hexane

→

tert-butyl 4-methylenepiperidine-1-carboxylate

収率 94.2%

溶媒

ether

ether

反応条件

後処理

1. 1
   温度at reflux for 2 hrs
2. 2
   温度to warm to room temperature
3. 3
   workup.STIRRINGstirred at room temperature for 1 h
4. 4
   workup.STIRRINGThe mixture was then stirred
5. 5
   温度at reflux overnight (16 h)
6. 6
   温度The mixture was cooled to room temperature
7. 7
   workup.STIRRINGThe mixture was stirred for 10 min
8. 8
   ろ過filtered
9. 9
   洗浄eluted with Hexane/EtOAc (100/100 mL)
10. 10
    濃縮The combined organic solution was concentrated
11. 11
    その他to give the residue which
12. 12
    その他was purified by CombiFlash (100 g silica gel column, EtOAc/Hex=0-30%)

実験手順

To a suspension of methyltriphenylphosphonium bromide (36.3 g, 101.6 mmol, 1.35 equiv) in ether (dry, 300 mL) was added potassium t-butoxide (11 g, 98 mmol, 1.3 equiv) in one portion at 0° C. under nitrogen balloon. The mixture was then stirred at reflux for 2 hrs. The hot reaction mixture was cooled to 0° C. with an external ice-bath and then a solution of tert-butyl 4-oxopiperidine-1-carboxylate (15 g, 75.3 mmol, 1.0 equiv) in ether (60 mL) was added dropwise. The mixture was allowed to warm to room temperature and stirred at room temperature for 1 h. The mixture was then stirred at reflux overnight (16 h). The mixture was cooled to room temperature and hexane (300 mL) was added. The mixture was stirred for 10 min, filtered and eluted with Hexane/EtOAc (100/100 mL). The combined organic solution was concentrated to give the residue which was purified by CombiFlash (100 g silica gel column, EtOAc/Hex=0-30%) to afford 14 g (yield 94%) of tert-butyl 4-methylenepiperidine-1-carboxylate as a colorless oil.

出典