Synthesis of Retigeranic Acid

Structure of Retigeranic Acid

C25H38O2

Principal investigatorPaul A. Wender
Publication year1990
Synthesis typeTotal
Number of steps 23 (3 parts)
References
Part 1 of 3
intermediate structure
Pig liver esterase
Buffer (pH = 7)
20 °C, , 94%
"Cristallized to >99 % ee."
intermediate structure
2,2?-Dipyridyl disulfide, Ph3P
CH2Cl2
RT, 36 h, 96%
intermediate structure + intermediate structure
Li, CuI
Et2O
-78 to 0 °C, 5 h, 90%
intermediate structure
LiAlH4
Et2O
intermediate structure
H2, Pd/C, HClO4
EtOH
RT, 15 h, 93% (2 steps)
intermediate structure
  1. o-NO2PhSeCN
  2. n-Bu3P
  3. H2O2
  4. H2O
THF
84%
intermediate structure
Cyclohexane
7 h, 24%
"Also isolate was a regioisomer (48 % yield) which was photoisomerized to the desired product."
intermediate structure
HCONH2
Acetone, t-BuOH
7 h
"Yield not reported."
intermediate structure
KOH, MeI
DMSO
RT, 48 h, 54%
"The yield was 80 % at 67 % conversion."
intermediate structure
SeO2, t-BuOOH
DCE
Reflux, 23 h, 53%
intermediate structure
Part 2 of 3
intermediate structure
H2, (Ph3P)3RhCl
PhH
RT, 3.5 h, 90-94%
intermediate structure
Br2
AcOH
intermediate structure
KOH
H2O
intermediate structure
Ph3P+CH3 Br-, n-BuLi
THF
See the Wittig Reaction
intermediate structure
Part 3 of 3
intermediate structure + intermediate structure
i-Pr2NLi
THF
-78 to 50 °C, 5 h
See the Aldol Addition
intermediate structure
CH(OMe)2NMe2
AcOH
Reflux, 2 h, 65% (2 steps)
intermediate structure
PhMe
250 °C, 22 h, 44%
"Also isolate was the C14-epimer (24 % yield)."
intermediate structure
mCPBA, NaOAc
CH2Cl2
RT, 24 h
intermediate structure
KOt-Bu
DMSO
100 °C
intermediate structure
H2, Pd/C
PhH
RT, 14 d, 25%
"Also isolated was the C2-epimer (28 % yield) and internal alkenes (43 % yield) which were recycled."
intermediate structure
LiAlH4
THF
-5 °C to RT, 14 h
"Yield not reported."
intermediate structure + intermediate structure
HCrO3Cl.Pyr
CH2Cl2
RT, 4 h
"Yield not reported."
intermediate structure
NaClO2, NaH2PO4, 2-Methyl-2-butene
t-BuOH, H2O
RT, 30 min, 85%
intermediate structure