Synthesis of Ginkgolide B

C20H24O10
Principal investigator | Elias J. Corey |
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Publication year | 1988 |
Synthesis type | Total |
Number of steps | 26 (2 parts) |
References |
Part 1 of 2
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(COCl)2
PhH
RT, 85%

BF3.OEt2
CH2Cl2
-20 °C, 92%

Part 2 of 2
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- i-Pr2NLi
- PhNTf2
DME
-78 °C to RT, 4 h, 80%



- Cy2BH
- AcOH
THF
0 °C to RT, 18.5 h, 70%

(COCl)2,
n-Bu3N
PhH, PhMe
RT to Reflux, 3 h, 71%


TiCl4,
HS(CH2)3SH
CH2Cl2
0 °C to RT, 50 min, 98%

H2Cr2O7.2Pyr,
AcOH
3 Å MS
CH2Cl2
0 °C, 60 min, 75%

HIO4,
H2O
CH2Cl2, MeOH
-30 °C to RT, 60 min, 80%

Camphorsulfonic acid
MeOH
RT, 80%


Et2NLi
-25 to 0 °C, 45 min

Camphorsulfonic acid
CH2Cl2
RT, 24 h, 75% (2 steps)




AgNO3
MeCN
RT, 15 min, 50%
"Also isolated were two allylic nitrates, both of which were converted to the desired product. The overall yield for these transformations is shown."

Pyr,
Pyr.TsOH
PhCl
135 °C, 16 h, 80%



Camphorsulfonic acid
CH2Cl2
RT, 15 h, 82%

TBSOTf,
2,6-Lutidine
MeCN
RT, 60 min, 89%

OsO4
Pyr

I2,
CaCO3
MeOH
RT, 12 h, 40% (2 steps)

BF3.OEt2
CH2Cl2
RT, 14 h, 89%
