Synthesis of Fredericamycin A

C30H21NO9
Principal investigator | Dale L. Boger |
---|---|
Publication year | 1995 |
Synthesis type | Total |
Number of steps | 27 (3 parts) |
References |
Part 1 of 3

MeOCH2Cl,
n-Bu4N+ I-,
NaH
DMF
0 °C to RT, 24 h, 91%


KOH
H2O, MeOH
RT, 12 h, 85% (2 steps)

n-Bu4N+ I-,
NaH,
MeOCH2Cl
DMF
RT, 72 h, 71%

Cr(CO)6,
n-BuLi
Et2O
-78 °C to RT, 2.5 h

Me3O+BF4-
CH2Cl2
0 °C to RT, 90 min, 78% (2 steps)

Part 2 of 3
+
+
+
+

Et3N,
MeSOCl
CCl4
0 °C, 10 min



DBU
THF
70 °C, 40 h, 81-91%



DDQ
CH2Cl2
RT, 10 min, 87%



i-Bu2AlH
THF
-78 °C, 3 h, 97%



n-BuLi
THF
-78 °C to RT, ON, 89%
See the Wittig Reaction
"Ratio of the cis-cis, cis-trans, trans-cis and trans-trans isomers, respectively."

I2
CHCl3
RT, 4-5 d

i-Bu2AlH
PhMe
-30 °C, 60 min, 69% (2 steps)


n-BuLi
THF
-78 to 0 °C, 2.5 h
"Mixture of diastereoisomers."

Imidazole,
TBSCl
DMF
RT, 22 h, 54% (2 steps)

Part 3 of 3
+




n-Bu4N+ F-
THF
RT to 50 °C, 10.5 h



- BBr3
- HCl , O2 , H2O
CH2Cl2
-78 °C to RT, 4 h
"Partial deprotection of the imide."

TsOH,
NaBr
MeOH
70 °C, 12 h, 85% (2 steps)
