Synthesis of Echinopine A

Structure of Echinopine A

C15H20O2

Principal investigatorGuangxin Liang
Publication year2013
Synthesis typeTotal
Number of steps 18 (linear)
References
Org. Lett. 2013, 15, 1978.
Part 1 of 1
intermediate structure + intermediate structure
i-Pr2NLi
THF
-78 °C to RT, 2.5 h
See the Aldol Addition
See the Henry Reaction
intermediate structure
DMSO, Et3N, Pyr.SO3
CH2Cl2
RT, ON, 25% (2 steps)
See the Parikh-Doering Oxidation
"Also isolated was 26% of the C2 epimer which was epimerized to the desired isomer (Et3N/DCM) in 80% yield."
intermediate structure
(CH2OH)2, TsOH
PhMe
Reflux, 96%
intermediate structure
H2, Pd/C
1 atm
MeOH
RT, 10 h, 99%
intermediate structure
(CO2H)2, NaNO2
H2O
RT, 12 h, 77%
See the Tiffeneau-Demjanov Rearrangement
intermediate structure
n-BuLi, Ph3P+CH3 Br-
THF
0 °C to RT, 2.5 h, 53%
See the Wittig Reaction
intermediate structure
NHMeOMe.HCl, i-PrMgBr
THF
-20 °C, 1 h, 94%
intermediate structure
MeMgBr
THF
-30 to -5 °C, 1 h, 98%
See the Weinreb Ketone Synthesis
intermediate structure
  1. TMS2NK
  2. PhNTf2
THF
-78 °C, 2.5 h, 98%
intermediate structure
CO, Et3N, Pd(OAc)2, Ph3P
DMF, MeOH
RT, 5 h, 79%
intermediate structure
H2O, HCl
MeOH, THF
RT, 2 h, 97%
intermediate structure
TsNHNH2
MeOH
RT, 24 h
intermediate structure
K2CO3
PhMe
130 °C, 10 h, 68% (2 steps)
See the Huisgen Cycloaddition
intermediate structure
hv
PhH
6 h, 66%
intermediate structure
LiOH
H2O, MeOH
100 °C, 9 h, 96%
intermediate structure
Ph3P, Cl3CCN
CH2Cl2
RT, 1 h
intermediate structure
CH2N2, Et3N
Et2O
0 °C to RT
intermediate structure
PhCO2Ag
H2O, THF
RT, 8 h, 41% (3 steps)
See the Wolff Rearrangement
intermediate structure
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