Synthesis of Pseudolaric Acid B

C23H28O8
Principal investigator | Barry M. Trost |
---|---|
Publication year | 2007 |
Synthesis type | Total |
Number of steps | 31 (3 parts) |
References |
Part 1 of 3

H2,
(R)-BINAP,
[RuI2(p-cymene)]2
120 atm
CH2Cl2, MeOH
40 °C, 24 h, 95%
See the Noyori Asymmetric Hydrogenation

TBSCl,
Imidazole,
DMAP
DMF
RT, 14 h

i-Bu2AlH
PhMe
-78 °C, 60 min

- i-Pr2NLi , TMSCHN2
- TMSCl
THF
-78 to 0 °C, 11 h, 73% (3 steps)


Part 2 of 3

Imidazole,
TBDPSCl
THF
RT, 18 h, 92%



Part 3 of 3
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K2CO3
CH2Cl2, MeOH
RT, 21 h, 58% (2 steps)


DCE
0 °C to RT, 90 min, 88%

n-Bu4N+ F-
THF
0 °C to RT, 4 h, 94%

DMAP,
Imidazole,
TESCl
DMF
0 °C to RT, 16 h, 85%


i-Pr2NLi
THF
-10 °C, 40 min, 72% (2 steps)

DDQ
CH2Cl2, Buffer (pH = 7)
0 °C, 15 min

KCN,
MnO2,
AcOH
MeOH
RT, 10 h, 85% (2 steps)

n-Bu4N+ F-,
AcOH
THF
RT, 18 h, 87%

CDI
THF
RT, 24 h, 100%

(PhSe)2,
NaBH4
DMF
RT, 8 h, 92%

Cl3C(=NH)OCH2(p-MeOPh),
Sc(OTf)3
PhMe
0 °C, 2 h, 94%

DCC,
DBU,
n-Bu3SnH
PhH
RT to 70 °C, 20 h, 85%

- KOTMS
- TsOH , i-Pr2NEt , Me2SO4
µW
MeOH, PhMe
100 to 120 °C, 45 min

NaHCO3,
Dess-Martin Periodinane
CH2Cl2
0 °C, 60 min, 59% (2 steps)
See the Dess-Martin Oxidation
"The yield was 73 % brsm."

DDQ
CH2Cl2, Buffer (pH = 7)
0 °C to RT, 60 min, 76%


LiCl,
CeCl3,
n-BuLi
THF
-78 °C, 2.5 h, 87%
"The yield was 98 % brsm."

[(Bu2SnNCS)2O]2
µW
PhMe
130 °C, 30 min, 94%

n-Bu4N+ F-
THF
0 °C to RT, 20 min, 87%

Sc(OTf)3
Ac2O
0 °C, 2 h, 98%

Pd(PPh3)2Cl2,
n-Bu3SnH
THF
RT, 15 min, 90%


