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OH
H
6
6'
O
O
HO
1
O
OH
HO
O
H
O
O
1'
H
OH
A
OH
OH
HO
6'
6
6
O
O
OH
1
HO
HO
1'
O
O
1
OH
HO
HO
HO
O
O
O
6'
H
H
OH
O
O
H
OH
O
1'
C
B
H
Fig. 3 The hydrogen bondings in sucrose molecule in the solid state (A) and in solution
(B and C).
OH
H
O
O
OR
O
NaH, THF
MOMO
O
O
BnO
O
1,4-diodo-
butane
O
BnO
O
OBn
OBn
BnO
O
OBn
OBn
BnO
OBn
OBn
13a
R = MOM
22
R = Bn
39
RCM
O
O
O
O
6
6'
O
O
Gluc
3xOBn
Fruc
3xOBn
OBn
O
O
O
O
BnO
40
OBn
O
OBn
O
O
BnO
BnO
OBn
OBn
42
O
OBn
OBn
BnO
OBn
Grubbs-I
41
removal of the blocks (with
simultaneous reduction of the
double bond) achieved by
hydrogenation over Pd/C
O
O
O
O
OBn
O
O
BnO
'free' macrocycles
O
OBn
BnO
OBn
43
OBn
Scheme 9 Connection of the C6 (glucose part) and C6' (fructose) position via a carbon
linker.
Connection of both terminal positions of sucrose by the RCM approach
was also possible for 'unsymmetrically' activated derivative 44, prepared
readily from 22. Cyclization induced by the Grubbs II catalyst afforded
monomer 46, cyclic dimer 45, and non-cyclic dimer 47 although the
yields were low (Scheme 10).
31
These results, proving that the terminal positions located in both
subunits can be connected via a bridge, opened a route to sucrose ana-
logs of crown and aza-crown ethers.
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