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, (R)-BINAP, [RuI2(p-cymene)]2
120 atm
CH2Cl2, MeOH
40 °C, 24 h, 95%
intermediate structure
TBSCl, Imidazole, DMAP
DMF
RT, 14 h
intermediate structure
i-Bu2AlH
PhMe
-78 °C, 60 min
intermediate structure
  1. i-Pr2NLi , TMSCHN2
  2. TMSCl
THF
-78 to 0 °C, 11 h, 73% (3 steps)
intermediate structure
Imidazole, I2, 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
Special reagent
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. PhLi , Ph3P+CH3 Br- , LiBr
  2. HCl
  3. KOt-Bu
MeOH, THF
-78 °C to RT, 18 min
intermediate structure
K2CO3
CH2Cl2, MeOH
RT, 21 h, 58% (2 steps)
intermediate structure
Special reagent
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
NaHCO3, mCPBA
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
KCN, MnO2, AcOH
MeOH
RT, 10 h, 85% (2 steps)
intermediate structure
n-Bu4N+ F-, AcOH
THF
RT, 18 h, 87%
intermediate structure
CDI
THF
RT, 24 h, 100%
intermediate structure
(PhSe)2, NaBH4
DMF
RT, 8 h, 92%
intermediate structure
Cl3C(=NH)OCH2(p-MeOPh), Sc(OTf)3
PhMe
0 °C, 2 h, 94%
intermediate structure
DCC, DBU, n-Bu3SnH
PhH
RT to 70 °C, 20 h, 85%
intermediate structure
  1. KOTMS
  2. TsOH , i-Pr2NEt , Me2SO4
µW
MeOH, PhMe
100 to 120 °C, 45 min
intermediate structure
NaHCO3, Dess-Martin Periodinane
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, CeCl3, n-BuLi
THF
-78 °C, 2.5 h, 87%
"The yield was 98 % brsm."
intermediate structure
[(Bu2SnNCS)2O]2
µW
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
Pd(PPh3)2Cl2, n-Bu3SnH
THF
RT, 15 min, 90%
intermediate structure + intermediate structure
Pd2(dba)3, i-Pr2NEt
NMP
RT, 22 h, 62%
See the Stille Coupling
intermediate structure