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OH
O
OH
HO
2
C
O
O
HO
HO
N
N
NHAc
HO
N
OH
9
OBn
BnO
N
N
O
N
BnO
O
BnO
BnO
BnO
BnO
OMe
10
FIGURE 9.4
Disaccharide mimics available from simple sugars by click approach.
Similarly, other disaccharide mimics such as
9
[23] or
10
[24] (Fig. 9.4) were
prepared. The azide and acetylene functionalities can be introduced at the desired
position of carbohydrate, which makes possible not only convenient synthesis of
natural important carbohydrate mimics but also allows for planning the structure of
various analogs.
“Click” analogs of important higher sugars such as sialic acid were also prepared
in a relatively simple way. For example, the azide
11
can be converted either into
the dimer (by reaction with acetylenic derivative of sialic acid) or, via the “click”
intermediate
12
, to dendrimeric derivatives (Fig. 9.5) [25].
Application of this approach to oligosaccharides is rather limited, although this
methodology provides an easy and rather simple way to biologically interesting
molecules obtained by relatively easy coupling of disaccharides (or even oligosac-
charides). For example, compounds
16
and
17
(representing a new class of glycocon-
jugate benzene sulfonamides) were easily prepared and further applied in biological
tests against Human Isozymes hCA I, II, and IX (Fig. 9.6) [26].
Dendrimeric structures containing the galabiose and galatriose units were also
prepared (such as
18
and
19
in Fig. 9.7) [27].
Carbohydrates (mono-, oligo- or cyclic, e.g., cyclodextrins) are often used as
stationary phases in the HPLC technique. The combination of polar stationary phases
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