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SO
2
NH
2
OAc
O
OAc
AcO
AcO
+
AcO
O
N
3
O
AcO
AcO
X
O
13
14
: X = O,
15
: X = NH
SO
2
NH
2
OAc
O
OAc
X
O
AcO
AcO
AcO
O
N
N
O
N
AcO
16
: X = O;
17
: X = NH
AcO
FIGURE 9.6
Glycoconjugate benzene sulfonamides prepared by click approach.
poor solubility in most organic solvents, presence of eight hydroxyl groups which are
difficult to differentiate, and high sensitivity of the glycosidic bond in acidic media.
As a part of an ongoing program, we have elaborated a convenient route to
1
,2,3,3
,4,4
-hexa-
O
-benzylsucrose [41] (
26
), useful starting material for the prepa-
ration of derivatives modified at the terminal (C6,C6
) positions. Diol
26
also seemed
to be a convenient starting material for the preparation of crown ether analogs with
sucrose scaffold (Fig. 9.10) [42].
Such compounds possess interesting complexing properties and may be used as
chiral receptors for the recognition of quaternary ammonium salts (e.g., derived from
amines, amino acids). We have shown that some of them display interesting enan-
tioselectivity toward
-phenylethyl-ammonium chloride. For example, compound
29
showed remarkable enantioselectivity toward the
S
-enantiomer (K
S
/K
R
=
1.5),
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