Synthesis of Pseudolaric Acid B

Structure of Pseudolaric Acid B

C23H28O8

Principal investigatorBarry M. Trost
Publication year2007
Synthesis typeTotal
Number of steps 31 (3 parts)
References
Part 1 of 3
intermediate structure
H2, [RuI2(p-cymene)]2, (R)-BINAP
CH2Cl2, MeOH
40 °C, 24 h, 95%
intermediate structure
DMAP, Imidazole, TBSCl
DMF
RT, 14 h
intermediate structure
i-Bu2AlH
PhMe
-78 °C, 60 min
intermediate structure
  1. i-Pr2NLi
  2. TMSCl
  3. TMSCHN2
THF
-78 to 0 °C, 11 h, 73% (3 steps)
intermediate structure
I2, Imidazole, Ph3P
PhMe
RT, 60 min, 90%
See the Appel Reaction
intermediate structure
Part 2 of 3
intermediate structure
Imidazole, TBDPSCl
THF
RT, 18 h, 92%
intermediate structure
Et2Zn, CH2I2
CH2Cl2, DME
-10 °C to RT, 14.5 h, 91%
intermediate structure
(COCl)2, DMSO, Et3N
CH2Cl2
-78 °C to RT, 5.5 h, 100%
See the Swern Oxidation
intermediate structure
Part 3 of 3
intermediate structure + intermediate structure
  1. HCl
  2. KOt-Bu
  3. Ph3P+CH3 Br-
  4. LiBr
  5. PhLi
MeOH, THF
-78 °C to RT, 18 min
intermediate structure
K2CO3
CH2Cl2, MeOH
RT, 21 h, 58% (2 steps)
intermediate structure
DCE
0 °C to RT, 90 min, 88%
intermediate structure
n-Bu4N+ F-
THF
0 °C to RT, 4 h, 94%
intermediate structure
DMAP, Imidazole, TESCl
DMF
0 °C to RT, 16 h, 85%
intermediate structure
mCPBA, NaHCO3
CH2Cl2
-20 °C, 30 min
intermediate structure
i-Pr2NLi
THF
-10 °C, 40 min, 72% (2 steps)
intermediate structure
DDQ
CH2Cl2, Buffer (pH = 7)
0 °C, 15 min
intermediate structure
AcOH, MnO2, KCN
MeOH
RT, 10 h, 85% (2 steps)
intermediate structure
AcOH, n-Bu4N+ F-
THF
RT, 18 h, 87%
intermediate structure
CDI
THF
RT, 24 h, 100%
intermediate structure
NaBH4, (PhSe)2
DMF
RT, 8 h, 92%
intermediate structure
Sc(OTf)3, Cl3C(=NH)OCH2(p-MeOPh)
PhMe
0 °C, 2 h, 94%
intermediate structure
n-Bu3SnH, DBU, DCC
PhH
RT to 70 °C, 20 h, 85%
intermediate structure
  1. i-Pr2NEt
  2. Me2SO4
  3. TsOH
  4. KOTMS
MeOH, PhMe
100 to 120 °C, 45 min
intermediate structure
Dess-Martin Periodinane, NaHCO3
CH2Cl2
0 °C, 60 min, 59% (2 steps)
"The yield was 73 % brsm."
intermediate structure
DDQ
CH2Cl2, Buffer (pH = 7)
0 °C to RT, 60 min, 76%
intermediate structure + intermediate structure
LiCl, n-BuLi, CeCl3
THF
-78 °C, 2.5 h, 87%
"The yield was 98 % brsm."
intermediate structure
[(Bu2SnNCS)2O]2
PhMe
130 °C, 30 min, 94%
intermediate structure
n-Bu4N+ F-
THF
0 °C to RT, 20 min, 87%
intermediate structure
Sc(OTf)3
Ac2O
0 °C, 2 h, 98%
intermediate structure
n-Bu3SnH, Pd(PPh3)2Cl2
THF
RT, 15 min, 90%
intermediate structure + intermediate structure
i-Pr2NEt, Pd2(dba)3
NMP
RT, 22 h, 62%
See the Stille Coupling
intermediate structure