Claisen Condensation

Mechanism of the Claisen Condensation

Sample reactions


NaOEt
82 °C, 14 h, 63%


i-Pr2NLi, MeO2CCN
THF
-78 °C


NaOMe, HCO2Et
PhH
RT, 12 h


NaH, HCO2Et
THF
0 °C to RT, 3 h


NaOMe, HCO2Et
PhH
RT, 30 min, 94%


NaOMe, HCO2Et
PhH
RT, ON


i-Pr2NLi, CDI, MeOAc
THF
-78 to 0 °C, 4 h, 72% (2 steps)


TMS2NK, ClCO2Bn
THF
-78 °C, 6 h, 70%


i-Pr2NLi, MeO2CCN
HMPA, THF
-78 °C, 90 min, 89%



i-Pr2NLi
Et2O
-78 °C, 2 h


NaH, HCO2Et
THF
RT, 14 h, 83%


KH, HCO2Me
THF
RT, 8 h


n-BuLi, MeCN
THF
-88 to -78 °C, 60 min, 93%



NaH, HCO2Me
MeOH, THF
RT to 40 °C, 20 h, 100%



NaOMe, HCO2Me
PhH
95%



i-Pr2NLi
THF
-78 °C, 19 h, 72%
"The yield was 82 % brsm."


TMS2NLi
THF
Reflux, 30 min


NaH
PhH
81% (2 steps)


Na, HCO2Et
Et2O
100%


NaOEt, (CO2Et)2
PhH
RT, 4 h, 40%


i-Pr2NLi, EtOAc
Hexane(s), THF
-78 °C to RT, 55 min, 71%


NaH, EtOAc
PhMe
110 °C, 15 h


NaH
DME
Reflux, 17 h


NaH, HCO2Me
THF
0 °C, 17 h



ClCO2Et, Et3N
THF
0 °C to RT, ON, 77%


NaH, MeOAc, ClCH2CO2Me
DMF
50-60 °C, 4.5 h, 55%


NaH, (CO2Me)2
DMF, MeOH
35-80 °C, , 44%


NaOMe, HCO2Et
PhH
0 °C to RT, 20 h, 97%


NaOMe, HCO2Et
PhH
RT, ON



LDA
THF
-78 °C to RT, 8.5 h, 89%


H2O, HCl, NaH, n-BuLi
THF
-78 °C to Reflux, 42 h, 67%
