Synthesis of Zaragozic Acid C

C40H50O14
Principal investigator | David A. Evans |
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Publication year | 1994 |
Synthesis type | Total |
Number of steps | 29 (3 parts) |
References |
Part 1 of 3
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2,6-Lutidine,
TBSOTf
CH2Cl2
0 °C, 60 min

LiBH4
MeOH, THF
0 °C, 3.5 h


Part 2 of 3



Pyr.TsOH,
2,2-Dimethoxypropane
PhH
98%


""This iodide was readily prepared from intermediates previously reported by us""

Part 3 of 3
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TsOH,
Cyclopentanone dimethyl acetal
PhH
65 °C, 12 h, 85%

- TMS2NLi
- TMSCl
THF
-78 to 0 °C, 60 min, 97%








- O3 , Pyr
- Me2S
CH2Cl2
-78 °C to RT, 4 h


N,N'-diisopropyl-O-tert-butylisourea
CH2Cl2
24 h, 91% (3 steps)


t-BuLi
Et2O, Hexane(s)
-78 °C, 20 min, 73%

DDQ
CH2Cl2
60 min

Ac2O,
DMAP
PhH, Pyr
90% (2 steps)

H2O
CH2Cl2, CF3CO2H

N,N'-diisopropyl-O-tert-butylisourea
CH2Cl2
24 h, 52% (2 steps)

H2,
Pd/C
50 atm
AcOH, MeOH
20 h, 96%



n-Bu4N+ F-
THF
0 °C, 15 min, 99%

CF3CO2H
CH2Cl2
24 h, 99%
