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In-Depth Information
Ph
3
P, DMF, LiCl, rt, 3 h,
then, CBr
4
, 60°C, 24 h
OH
Br
NaN
3,
Me
2
SO, 80°C, 36 h
O
HO
O
HO
HO
O
O
HO
n
n
72
71
Lac
O
N
N
O
N
3
N
Lac
O
HO
O
O
HO
CuBr
2
, ascorbic acid, propylamine
rt, 12 h, Me
2
SO.
O
HO
HO
n
73
n
74
SCHEME 5.19
Synthesis of modified polysaccharides clicked with lactosides.
6)-mannosyltransferases by the triazole-linked oligomannosides was deter-
mined, the most active compounds were the hexa- and octamannoside analogs.
-(1
→
5.3 CLICKED CYCLODEXTRINS
Glycocyclodextrins can be considered well-defined glyco-oligomers, having sym-
metric tridimensional structures. For these reasons, cyclodextrins have been selected
as scaffolds for the synthesis of multivalent ligands by several groups of investigators
[40]. Perglycosylated cyclodextrins (CDs), exposing a variety of sugar moieties such
as
-D-glucosamine and even
sialyloligosaccharides, have been synthesized. A large variety of functional groups
have been used in order to connect the sugar residues to the platform: among them,
amide, urea, thiourea, and thioethers were constructed by photoaddition of thiols to
-D-glucose,
-D-galactose,
-D-mannose, N-acetyl-
CH
3
OH
O
HO
HO
N
3
OH
N
N
OBn
OBn
OH
N
O
O
O
BnO
BnO
HO
BnO
BnO
HO
n = 0-14
n
N
N
N
OH
OMOM
O
HO
77
75
76
HO
OH
SCHEME 5.20
Triazol-linked C-mannosides.
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