Synthesis of Pactamycin

C28H38N4O8
Principal investigator | Stephen Hanessian |
---|---|
Publication year | 2011 |
Synthesis type | Total |
Number of steps | 35 (linear) |
References |
Part 1 of 1
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p-MeOBzCl,
Et3N
CH2Cl2
RT, 2 h, 64%

SOCl2
MeCN
0 °C to RT, 10 h, 85%



TESOTf,
2,6-Lutidine
CH2Cl2
0 °C to RT, 2 h, 67% (2 steps)

i-Bu2AlH
CH2Cl2
-78 °C



- O3
- Me2S
CH2Cl2
-78 °C to RT, ON, 84%


Cl3CCOCl,
Pyr
CH2Cl2
RT, 8 h, 89%

H2O2,
NaOH
CH2Cl2, H2O, MeOH
0 °C, 2 h, 75%
See the Michael Addition
"Also isolated was the TES-deprotected product (16 % yield)."


Tf2O,
Pyr
CH2Cl2
-78 to 0 °C, 60 min

n-Bu4N+ N3-
4 Å MS
PhMe
RT, 3 d, 86% (2 steps)

CF3CO2H
H2O, MeCN
0 °C, 4 h, 93%



n-Bu4N+ F-
THF
0 °C to RT, 90 min, 95%


K2CO3
MeOH
0 °C to RT, 60 min, 87% (2 steps)

TBDPSCl,
Et3N,
DMAP
CH2Cl2
0 °C to RT, 4 h, 96%

Tf2O,
Pyr
CH2Cl2
-78 to 0 °C, 60 min, 96%


Yb(OTf)3
PhMe
80 °C, 9 h, 81%
"The yield was 91 % brsm."

HCl
H2O, THF
0 °C to RT, 14 h, 63%
"The yield was 83 % after two cycles."

TASF
CH2Cl2
0 °C to RT, 60 min, 95%

Camphorsulfonic acid,
2,2-Dimethoxypropane
CH2Cl2
0 °C to RT, 2 h, 86%

ClCO2CCl3,
Et3N
Activated charcoal
THF
-46 °C, 15 min, 89%

Me2NH
-46 °C to RT, 97%

i-Bu2AlH
CH2Cl2
-78 °C, 90 min, 90%


NaIO4
H2O, THF
RT, 3 h, 80% (2 steps)

CF3CO2H
H2O, MeCN
0 °C to RT, 45 min, 85%


K2CO3
DMA
RT, 70 min, 96%

Lindlar Catalyst,
H2
1 atm
EtOH, MeOH
RT, 3 h, 85%
