Synthesis of Phyllanthocin
C25H30O7
| Principal investigator | David R. Williams |
|---|---|
| Publication year | 1984 |
| Synthesis type | Total |
| Number of steps | 30 (3 parts) |
| References |
Part 1 of 3
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Me2CuLi
Et2O
-78 °C
TsOH,
3,4-Dihydropyran
LiAlH4
Et2O
RT, 18 h
TsOH
MsOH
RT, 70% (4 steps)
TsOH
Acetone
67%
"Also isolated was the 6-membered acetonide (13 % yield)."
TBDPSCl,
DMAP
CH2Cl2
RT, 2 h, 98%
(CH2SH)2,
TsOH
CHCl3
Reflux, 60 min
TsCl,
Et3N
CH2Cl2
36 h
NaH
THF
0 °C to RT, 76% (3 steps)
+
i-Pr2NEt,
DMAP,
MeO(CH2)2OCH2Cl
CH2Cl2
0 °C, 2 h, 95% (2 steps)
Part 2 of 3
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n-BuLi,
2,6-Dimethylpiperidine
Carius tube
Et2O
0 °C to 50 °C, 75 min, 90%
"Mixture of isomers."
Imidazole,
TBSCl
DMF
RT, 9 h, 34%
"Also isolated was the C5-epimer (45 % yield)."
BH3.THF,
H2O2
THF
0 °C to RT, 2 h, 46%
"Also isolated was the C2-epimer (19 % yield)."
+
<50%
"The experimental procedure for this resolution was unavailable in the article."
KOH
H2O, MeOH
"The experimental procedure for this resolution was unavailable in the article."
HCrO3Cl.Pyr
CH2Cl2
RT, 90%
Part 3 of 3
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+
+
n-Bu4N+ F-
THF
RT, 2 h, 51-61%
"The epimers were carried on separately."
HgO,
HgCl
H2O, MeCN
RT, 30 min, 42%
"The epimers were carried on separately. Also isolated were 2 isomeric spiroketals (38 % yield, see next step)."
CF3CO2H
CH2Cl2
0 °C, 1 min, 83%
"Also isolated was the desired CX-epimer (13% yield, see next step)."
MeMgCl,
CF3CO2H
CH2Cl2
RT, 6 h, 63%
Pd/C,
H2
EtOAc
RT, 45 min, 82%
CH2N2
Et2O
RT, 1 min, 100%
ZnBr2
CH2Cl2
RT, 2 h, 100%
+
DMAP
CH2Cl2
RT to 40 °C, 8 h, 73%