Claisen Condensation

Schematic representation of the Claisen Condensation.
Mechanism of the Claisen Condensation
Mechanism of the Claisen Condensation
Sample reactions
intermediate structure intermediate structure
NaOEt
82 °C, 14 h, 63%
intermediate structure
intermediate structure
i-Pr2NLi, MeO2CCN
THF
-78 °C
intermediate structure
intermediate structure
HCO2Et, NaOMe
PhH
RT, 12 h
intermediate structure
intermediate structure
NaH, HCO2Et
THF
0 °C to RT, 3 h
intermediate structure
intermediate structure
HCO2Et, NaOMe
PhH
RT, 30 min, 94%
intermediate structure
intermediate structure
HCO2Et, NaOMe
PhH
RT, ON
intermediate structure
intermediate structure
CDI, MeOAc, i-Pr2NLi
THF
-78 to 0 °C, 4 h, 72% (2 steps)
intermediate structure
intermediate structure
TMS2NK, ClCO2Bn
THF
-78 °C, 6 h, 70%
intermediate structure
intermediate structure
i-Pr2NLi, MeO2CCN
THF, HMPA
-78 °C, 90 min, 89%
intermediate structure
intermediate structure intermediate structure
i-Pr2NLi
Et2O
-78 °C, 2 h
intermediate structure
intermediate structure
NaH, HCO2Et
THF
RT, 14 h, 83%
intermediate structure
intermediate structure
KH, HCO2Me
THF
RT, 8 h
intermediate structure
intermediate structure
n-BuLi, MeCN
THF
-88 to -78 °C, 60 min, 93%
intermediate structure
intermediate structure intermediate structure
NaH, HCO2Me
THF, MeOH
RT to 40 °C, 20 h, 100%
intermediate structure intermediate structure
intermediate structure
HCO2Me, NaOMe
PhH
95%
intermediate structure
intermediate structure intermediate structure
i-Pr2NLi
THF
-78 °C, 19 h, 72%
"The yield was 82 % brsm."
intermediate structure
intermediate structure
TMS2NLi
THF
Reflux, 30 min
intermediate structure
intermediate structure
NaH
PhH
81% (2 steps)
intermediate structure
intermediate structure
Na, HCO2Et
Et2O
100%
intermediate structure
intermediate structure
(CO2Et)2, NaOEt
PhH
RT, 4 h, 40%
intermediate structure
intermediate structure
i-Pr2NLi, EtOAc
THF, Hexane(s)
-78 °C to RT, 55 min, 71%
intermediate structure
intermediate structure
NaH, EtOAc
PhMe
110 °C, 15 h
intermediate structure
intermediate structure
NaH
DME
Reflux, 17 h
intermediate structure
intermediate structure
HCO2Me, NaH
THF
0 °C, 17 h
intermediate structure
intermediate structure intermediate structure
ClCO2Et, Et3N
THF
0 °C to RT, ON, 77%
intermediate structure
intermediate structure
NaH, MeOAc, ClCH2CO2Me
DMF
50-60 °C, 4.5 h, 55%
intermediate structure
intermediate structure
(CO2Me)2, NaH
DMF, MeOH
35-80 °C, , 44%
intermediate structure
intermediate structure
HCO2Et, NaOMe
PhH
0 °C to RT, 20 h, 97%
intermediate structure