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2. Synthetic Utilization of pentafulvenes
2. Development of Synthetic Methodologies towards Fused Cyclooctanoids
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HO
O
OH
H
H
H
O
Dactylol
HO
H
O
H
O
OH
H
HO
H
H
O
H
H
O
H
OH
OH
O
O
O
Lancifodilactone G
Anti-HIV active
Kalmanol
Asteriscanolide
O
O
OH
OH
Some of the Biologically active cyclooctanoids
 Developed a Novel Methodology for the synthesis of 5-8 fused Cyclooctanoids
R
R1
R
O
AcO
O
O
CHCl3
Et3N
R1
O
O
[6+3]
O
Tet. Lett. 2005, 46, 4785-4788
Utilization of the Developed Synthetic Methodology
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O
N
O
N Ph
Bn
H
O
O
N Bn
H
Toluene, RT
TFA
O
O
O
O
H
N
Ph
O
O
O
Et3N
AcO
O
R2
O
O
R2
R2
Tet. Lett. 2005, 46, 4785-4788
O
O
Tetrahedron, 2006, 5952-5961
O
O
Tetrahedron, 2006, 62, 12345;
Synthesis, 2006,11, 1811-1818
Eur. J. Org. Chem. 2007, 5847
R1
Syn-anti
O
R1
Syn-syn
O
 Novel route to eleven membered rings and spirocyclic cyclooctanoids
O
O
R
Synthesis, 2008, 13, 2134
Pd/C
O
O
O
O
R
AcO
NaIO4
R
O
R
O
RuCl3.3H2O
i. CPD, base
ii.
O
H
O
O
H
Eur. J. Org. Chem.
2007, 5847
H2
H
OH
O
Neodolabellane
O
O
O
O
“Heterocycles via Pyrylium and Pyridinium Betaines”, K. V. Radhakrishnan,
Topics in Heterocyclic Chemistry, Vol. Synthesis of Heterocycles via Cycloadditions, 13, 2008,
pages-71-98., Springer.
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3. Synthetic Carbohydrate Chemistry
 Design, Synthesis and Host-Guest Evaluation of Neoglycoconjugates
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Ionic liquid [bmim]PF6 Mediated Synthesis of 1,2-Orthoesters of Carbohydrates
 1,2-Orthoesters- Important Intermediates in Synthetic Carbohydrate Chemistry
For eg: n-Pentenyl Orthoesters as Glycoside Donors
Br
PF6
N
H3C
[bmim]PF6

O
R-OH
O
N
2,6-Lutidine
[bmim]PF6
O
OR
BzO
O
OBz
Ph
We have developed a facile and environmentally benign method for the
synthesis of 1,2- orthoesters of carbohydrates and Glycosidation reactions of
NPOE in ionic liquid [bmim]PF6.

The method is much simpler and the solvent can be reused several times
Synlett, 2005, 6, 997
Bull. Chem. Soc. Jpn. 2007, 553.
Synthesis and Study of Carbohydrate Appended Mutivalent ligands
 Synthesis of higher order glycoconjugates as probes to
define the molecular nature of carbohydrate-receptor
interactions
 Interaction of metal ions with carbohydrates is an important element for
biochemical processes
 Metal complexes involving carbohydrates clarify many functions of
carbohydrates in natural systems
Carbohydrates as Scaffolds by attaching
a chelating ligand for cation and anion binding
Synthesis and study of Carbohydrate-coated Nanocapsules
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 Photochromic nanocapsules
 Multivalent nanoscaffolds for selective
interactions
Able to encapsulate guest molecules
Target selective nanocarriers
Vesicles
Labelling specific protein
Sensing of a range of pathogens.
Nanorods