Synthesis of Yohimbine

C21H26N2O3
Principal investigator | Eugene E. van Tamelen |
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Publication year | 1958 |
Synthesis type | Formal |
Number of steps | 20 (linear) |
References |
Part 1 of 1
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Zn
AcOH
30-50 °C, 40 min, 93%


NaOH
H2O
RT to 100 °C, 45 min, 87%

Cu
Diethylene glycol
155-160 °C, 2 h, 76%


(COCl)2,
Pyr
Et2O
RT, 8 h


Pyr
CHCl3
5 °C, 10 h, 75% (2 steps)

Pyr,
OsO4
Et2O, THF
-78 °C, 2.5 h, 56%
"Single, unidentified cis-isomer. Also isolated was the other cis-diastereoisomer (11 % yield)."

PtO2,
H2
EtOH
RT, 60 min, 85%


TsOH
MeOH
RT, 3 d, 77%

LiAlH4
THF
Reflux, 4 h, 76%

HCl
H2O
100 °C, 3 h, 82%

Ac2O
Pyr
RT, ON

285-295 °C, 5 min, 71% (2 steps)

OsO4,
Pyr
THF
-78 °C, 7 h, 37%

NaIO4
H2O, MeOH
0 °C, 2 h, 81%


Remaining...
65% (2 steps)
"See : Acta Chim. Scand. 1956, 10, 1414."
