Synthesis of B-Araneosene

Structure of B-Araneosene

C20H32

Principal investigatorElias J. Corey
Publication year2005
Synthesis typeTotal
Number of steps 17 (linear)
References
Part 1 of 1
intermediate structure
Camphorsulfonic acid
H2O, MeCN
RT, 2 h
intermediate structure
Camphorsulfonic acid
Acetone
RT, 3 h, 80% (2 steps)
intermediate structure
MsCl, Et3N
Pentane, PhH
0 °C, 1.5 h
intermediate structure
LiI
THF
0 °C, 30 min
intermediate structure
Special reagent
LDA
THF
-90 to -78 °C, 8 h, 64%
intermediate structure
NaOMe
MeOH
50 °C, 30 min, 96%
intermediate structure
Ac2O, DMSO
RT, 24 h, 99%
intermediate structure
EtMgBr, ClTi(Oi-Pr)3
THF
0 °C to RT, 48 h, 60%
intermediate structure
AlMe3
CH2Cl2
-10 to 4 °C, 72 h, 90%
intermediate structure
  1. H2O
  2. NaIO4
AcOH
RT to 55 °C, 3.5 h, 92%
intermediate structure
SmI2
THF
Reflux, 2.5 h, 78%
intermediate structure
(COCl)2, DMSO, Et3N
CH2Cl2
-78 to 4 °C, 13 h
See the Swern Oxidation
intermediate structure
LiAlH4
THF
Reflux, 10 min, 74%
"Also isolated was the C-2 epimer (20% yield)"
intermediate structure
Et3N, MsCl
-30 to 4 °C, 73 h, 98%
intermediate structure
t-BuLi, 2-bromopropene
Et2O
-10 °C, 30 min, 82% (95% brsm)
intermediate structure
i-Pr2NEt, MeOCH2Cl, n-Bu4N+ I-
THF
67 °C, 6 h, 92%
intermediate structure
Li
NH3, THF
-60 °C, 3 h, 100%
intermediate structure