REU POSTER
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Synthesis of Epoxydine A Analogues Via Palladium-Catalyzed Cyclitolization Karol Rogelle Francisco *, Yu Li**, George O’Doherty** Barnard College, New York, NY* Northeastern University, Boston, MA** BACKGROUND POSSIBLE DIMERS RESULTS FUTURE/ONGOING WORK Epoxydine A is a naturally occurring compound that has been isolated from a fungus, endophyte salsola oppossifolia. It has been shown to have important anti-bacterial properties that may be pharmacologically important. Reported [α] = +71.9 (DCM, 0.3) Analysis of the NMR and optical rotation data lead the us to believe that the proposed structure is incorrect. Krohn, K. Helv. Chim. Acta. 2010, 93, 169-174 PROTECTED MONOMERS an, M., O’Doherty, G. Org. Lett. 2008, 10, 3381-3384. POSSIBLE STRUCTURES CYCLITOLIZATION X X The spectral data lead us to conclude that the correct structure is either the αL-βL dimer or the αD- βL dimer (or either enantiomer). As our synthesis αD-βL dimer did not match the reported spectral data for epoxydine A, we have concluded that the correct structure is either the αL-βL dimer or its enantiomer (αD-βD). The O’Doherty group is currently in the process of synthesizing all 10 analogues of epoxydine A and characterizing them. The group intends to use this antibacterial structure activity relationships to design new antibacterial agents. ACKNOWLEDGMENTS Northeastern University Chemistry Department National Science Foundation O’Doherty Research Group Dr. Oyinda Oyelaran Dr. Patricia Mabrouk Dr. Carla Mattos Professor Dina Merrer Professor Christian Rojas Dean Michell Tollinchi-Michel Con Edison Research Grant (Barnard College) DIMERIZATION Shan, M., O’Doherty, G. Org. Lett. 2010, 12, 2986-2989. O O O Epoxydine A O O O O OBoc OPNBz OBoc OBoc D D L L O O O O O OH Pd(0)(L) 2 H 2 O O O O O Pd(0)(L) 2 O OH D- D O O O D D D D O Pd L L t-BuOCO 2 O Pd L L t-BuOCO 2 O OBoc L O OBoc D O OBoc L O OPNBz D O OH D O OH L O OH L O OH D O O L- L O O O D- L O O O L L O O D- L O O O D- L O O O L D O O O D D O O O L L O O O D L O O L- L O O L- D O O O D D O O O D- D O O O L- D O O O D- L O O O D- D (S) (S) O O (S) (R) O (S) (S) O O (S) (S) O D L D - D (R) (S) O O (R) (R) O (R) (R) O O (S) (R) O L L D - L (R) (R) O O (R) (R) O L- L (R) (S) O O (R) (S) O D - D (R) (S) O O (S) (R) O (S) (S) O O (R) (R) O D L L D (S) (R) O O (S) (R) O L L (S) (S) O O (R) (S) O D D O O O L L O O O D - D O O O L D O O O D - D O O O D L O O O D L O OBoc D Pd catalyst, Ligand H 2 O, solvent O OH D O OBoc + O OH D L Pd catalyst, Ligand solvent O O O D L
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Transcript of REU POSTER
Synthesis of Epoxydine A Analogues Via Palladium-Catalyzed Cyclitolization
Karol Rogelle Francisco*, Yu Li**, George O’Doherty**Barnard College, New York, NY*
Northeastern University, Boston, MA**
BACKGROUND
POSSIBLE DIMERS
RESULTS
FUTURE/ONGOING WORK
Epoxydine A is a naturally occurring compound that has been isolated from a fungus, endophyte salsola oppossifolia. It has been shown to have important anti-bacterial properties that may be pharmacologically important.
Reported [α] = +71.9 (DCM, 0.3)
O
O O
Epoxydine A
Analysis of the NMR and optical rotation data lead the us to believe that the proposed structure is incorrect.
Krohn, K. Helv. Chim. Acta. 2010, 93, 169-174
PROTECTED MONOMERSOO OO
OBoc OPNBzOBoc OBocD DL L
Shan, M., O’Doherty, G. Org. Lett. 2008, 10, 3381-3384.
POSSIBLE STRUCTURES
O
O
O
O
O
OH
Pd(0)(L)2H2O
O
O
O
O
Pd(0)(L)2
O
OH
D-DO
O
O
D D
D
D
O
PdLL
t-BuOCO2
O
PdLL
t-BuOCO2
CYCLITOLIZATION
O
OBocL
O
OBocD
O
OBocL
O
OPNBzD
O
OH
D
O
OHL
O
OHL
O
OHD
O
O
O
L-L
O
O
OD-L
O
O
O
L L
O
O
O
D-L
O
O
OD-L
O
O
O
L D
O
O
O
DD
O
O
O
L L
O
O
O
D L
O
O
OL-L
O
O
O
L-D
O
O
O
DD
O
O
O
D-D
O
O
OL-D
O
O
O
D-L
O
O
OD-D
XX
(S)(S)
O
O(S)(R)
O
(S)(S)
O
O(S)(S)
O
D L
D-D
(R)(S)
O
O(R)(R)
O
(R)(R)
O
O(S)(R)
OL LD-L
(R)(R)
O
O(R)(R)
OL-L
(R)(S)
O
O(R)(S)
OD-D
(R)(S)
O
O(S)(R)
O
(S)(S)
O
O(R)(R)
OD L L D
(S)(R)
O
O(S)(R)
OL L
(S)(S)
O
O(R)(S)
OD D
The spectral data lead us to conclude that the correct structure is either the αL-βL dimer or the αD-βL dimer (or either enantiomer). As our synthesis αD-βL dimer did not match the reported spectral data for epoxydine A, we have concluded that the correct structure is either the αL-βL dimer or its enantiomer (αD-βD).
O
O
O
L L
O
O
OD-D
O
O
O
L D
O
O
O
D-D
O
O
O
D L
O
O
O
D L
The O’Doherty group is currently in the process of synthesizing all 10 analogues of epoxydine A and characterizing them. The group intends to use this antibacterial structure activity relationships to design new antibacterial agents.
ACKNOWLEDGMENTSNortheastern University Chemistry Department National Science FoundationO’Doherty Research GroupDr. Oyinda OyelaranDr. Patricia MabroukDr. Carla MattosProfessor Dina MerrerProfessor Christian RojasDean Michell Tollinchi-MichelCon Edison Research Grant (Barnard College)
DIMERIZATIONO
OBoc
D
Pd catalyst, Ligand
H2O, solvent
O
OHD
O
OBoc
+
O
OH
D L
Pd catalyst, Ligand
solvent O
O
O
D L
Shan, M., O’Doherty, G. Org. Lett. 2010, 12, 2986-2989.
