反应详情

温度

-78 °C

7.4 ml of 1.6M n-butyl lithium/hexane solution was dropwise added to a THF solution (30 ml) of 8.41 g of ethyl 4-diethylphosphonocrotonate below -50° C. and stirred for 15 minutes at --78° C. . To this was dropwise added 25 ml of a THF solution of 5.0 g of the above-mentioned 1-t-butyloxycarbonyl-4-piperidinone. This was stirred for 20 minutes at -78° C. and then for 2 hours at -10° C. The reaction mixture was diluted with water and extracted three times with ethyl acetate. The organic layer was washed with 1N HCl, saturated NaHCO3, brine (twice each) and dried with magnesium sulfate. The solvent was removed by distillation under a reduced pressure. Thus, 7.70 g of ethyl 4-(1-t-butyloxycarbonyl-4-piperidylidene)-2-butenoate was obtained as a white solid.

1. stirringThis was stirred for 20 minutes at -78° C.
2. waitfor 2 hours at -10° C
3. extractionextracted three times with ethyl acetate
4. washThe organic layer was washed with 1N HCl, saturated NaHCO3, brine (twice each) and
5. dry with materialdried with magnesium sulfate
6. customThe solvent was removed by distillation under a reduced pressure