An improvement in the bending ability of a hinged trisaccharide with the assistance of a sugar - Sugar interaction

Article abstract of DOI:10.1002/chem.200500096

Hinged di- and trisaccharides incorporating 2,4-diamino-β-D-xylopyranoside as a hinge unit (Hin) were synthesized. Bridging of the diamino group of Hin by carbonylation or chelation to a metal ion results in a conformational change from ⁴C

Full text of DOI:10.1002/chem.200500096

DOI: 10.1002/chem.200500096
An Improvement in the Bending Ability of a Hinged Trisaccharide with the
Assistance of a Sugar––Sugar Interaction
Hideya Yuasa,*[a] Takuhiro Izumi,[a] Nobuyuki Mitsuhashi,[a] Yasuhiro Kajihara,[b] and
Hironobu Hashimoto[a]
Abstract: Hinged di- and trisaccharides
incorporating 2,4-diamino-b-d-xylopyr-
anoside as a hinge unit (Hin) were syn-
thesized. Bridging of the diamino
group of Hin by carbonylation or che-
lation to a metal ion results in a confor-
mational change from C1 to C4, which
in turn causes a bending of the oligo-
saccharides. In this study, the bending
abilities of the hinged oligosaccharides
were compared, in terms of the reactiv-
ities toward carbonylation and chela-
tion. Di- or trisaccharides containing a
6-O-glycosylated mannopyranoside or
galactopyranoside at their reducing
ends had bending abilities similar to
that of the Hin monosaccharide, proba-
bly because there were neither attrac-
tive nor repulsive interactions between
the reducing and nonreducing ends.
However, when Hin was attached at
O2 of methyl mannopyranoside
(ManaMe), the bending ability was de-
pendent on the nonreducing sugar and
the reaction conditions. Typically, a dis-
accharide—Hinb(1,2)ManaMe—was
difficult to bend under all the tested re-
action conditions, and the bent popula-
tion in the presence of ZnII was only
4%. On the other hand, a trisacchar-
ide—Mana(1,3)Hinb(1,2)ManaMe—
was bent immediately after the addi-
tion of ZnII or HgII, and the bent popu-
lation reached 75%, much larger than
those of all the other hinged trisacchar-
ides ever tested (<40%). This excel-
lent bending ability suggests an attrac-
tive interaction between the reducing
and nonreducing ends. The extended
conformation was recovered by the ad-
dition of triethylenetetramine, a metal
ion chelator. Reversible, quick, and ef-
ficient bending of the hinged trisac-
charide was thus achieved.
4
1
Keywords: bioorganic chemistry ·
carbohydrates
· hinged oligosac-
charides · molecular recognition ·
oligosaccharides
Introduction
ble polymers, the conformational variation of these poly-
mers[3] seems to be less than that of polypeptides, the poly-
mers permitting the complicated folding processes involved
in building proteins. Moreover, unlike poly- and oligosac-
charides, polypeptides can act as the movable components
of molecular machines, such as allosteric enzymes, motor
proteins, and chaperones.[4] On the other hand, recent stud-
ies revealed that hyaluronan, a glycosaminoglycan, is flexi-
ble enough to assume kink, fold, or bent structures through
a combination of glycosidic bond rotations (f, f, w), and a
biological function was ascribed to this flexibility.[5] Howev-
er, the movements of this glycosaminoglycan would be as
modest as those of the other oligosaccharides inasmuch as
only the glycosidic bonds are the sources of the flexibility,
and so its impact on these functions might be insufficient for
it to serve as a movable component of a molecular machine.
A lot of natural poly- and oligosaccharides are composed
A substantial number of natural poly- and oligosaccharides
function as reinforcing elements in biological systems, pro-
viding proteins, cells, organs, and even whole organisms with
mechanical stability.[1] Some oligosaccharides are ligands of
lectins and antibodies, through which they participate in
cell–cell recognition events, bacterial infections, or immune
systems.[2] Although the poly- and oligosaccharides are flexi-
[a] Prof. H. Yuasa, T. Izumi, N. Mitsuhashi, Prof. H. Hashimoto
Department of Life Science
Graduate School of Bioscience and Biotechnology
Tokyo Institute of Technology, 4259 B3 Nagatsutacho
Midoriku, Yokohama 226–8501 (Japan)
Fax: ( +81)45-924-5850
E-mail: hyuasa@bio.titech.ac.jp
[b] Prof. Y. Kajihara
4
of pyranosides fixed in the C1 conformation. The rigidity of
Graduate School of Integrated Science, Yokohama City University
22–2, Seto, Kanazawa-ku, Yokohama 236–0027 (Japan)
the pyranosides restricts the movement of oligosaccharides
to a great extent, so biological systems might have selected
peptides for the movable components of the molecular ma-
Supporting information for this article is available on the WWW
under http://www.chemeurj.org/ or from the author.
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Chem. Eur. J. 2005, 11, 6478 – 6490

FULL PAPER
chines. To make the poly- and oligosaccharides more flexi-
ble and thereby more useful for the construction of artificial
architectures, the ring flip of a monosaccharide unit is pre-
requisite. In this context, xylopyranosides are useful mono-
Results and Discussion
We synthesized three new hinged disaccharides (10, 13, 19)
and four new hinged trisaccharides (17, 23, 31) as shown in
Scheme 2. The disaccharide 10 was synthesized by glycosyla-
tion of methyl 2,4-diazido-2,4-dideoxy-b-d-xylopyranoside
(8) with per-O-acetylated galactopyranosyl trichloroacetimi-
date (7) as a glycosyl donor to give the protected disacchar-
ide 9, followed by deacetylation and reduction of the azide
groups. The disaccharides 13 and 19 were prepared by re-
duction of the azide groups and the benzyloxy groups of the
reported precursors 12 and 18.[7] The disaccharide precursor
27 for the synthesis of the trisaccharide 31 was obtained by
the stereoselective glycosylation of methyl 2,3,6-tri-O-
benzyl-a-d-galactopyranoside (25) with 2,4-diazido-2,4-di-
deoxy-b-d-xylopyranosyl trichloroacetimidate (24) as a gly-
cosyl donor, with subsequent deacetylation. The trisacchar-
ides (17, 23, 31) were synthesized in the same manner from
the disaccharide precursors (12, 18, 27). Glycosylation of the
disaccharides (12, 18, 27) with 2-O-acetyl-3,4,6-tri-O-benzyl-
a-d-mannopyranosyl trichloroacetimidate (11) gave the pro-
tected trisaccharides (14, 20, 28), which were then subjected
to deacetylation (15, 21, 29), reduction at the azido groups
(16, 22, 30), and reductive debenzylation to give the desired
1
saccharides, since the ring flip is easy and the C4 conforma-
tion could be fixed as, for example, a 2,4-boronate deriva-
tive.[6] In this connection, the authors have succeeded in
bending a trisaccharide—Galb(1,3)Hinb(1,2)ManaMe (1;
4
Scheme 1)—through a C1–1C4 ring flip of the hinge sugar
Scheme 1. The extended and bent states of a hinged trisaccharide.
3
unit: 2,4-diamino-2,4-dideoxy-b-d-xylopyranoside (Hin). In
solution, Hin assumes the 4C1 conformation, the extended
trisaccharides (17, 23, 31). Large J values were observed for
the ring protons of the hinge units in all the synthesized di-
and trisaccharides, indicating the assumption of a C1 confor-
mation by the corresponding hinge unit in solution.
4
ꢀ
ꢀ
conformation with regard to C1 O1 and C3 O3 bonds, and
4
it falls into a C1–1C4 equilibrium in the presence of ZnII or
HgII, due to chelation by the diaxial amino groups of the
bent C4 conformers 2 and 3 (Scheme 1).[7] The bent struc-
1
Table 1. Comparison of the bending abilities of the hinged mono-, di-,
and trisaccharides in the presence of Zn(OAc)2 or Hg(OAc)2, in terms of
the C4 population of the hinge unit.
ture was transient in the exchanging metal complex forma-
tion, but was isolable as an N,N’-carbonyl derivative 4 or a
PtII complex 5 at the expense of long reaction times.[8] Such
a sharply bent structure had been unachievable with any
combinations of glycosidic bond rotations or heparin-like
conformational changes of the pyranosides. This unusual
bent structure, which is switchable from and to the extended
counterpart through chelation and dechelation, would thus
extend the scope of oligosaccharides as raw materials for
functional polymers and molecular devices. In practice, we
have synthesized a metal fluorosensor through the use of
this hinge sugar as a pivot for the tongs-like movement of
this molecular device.[9]
1
Compd
R1
R2
Metal ion
Equiv
1C4 (%)
monosaccharide
32
32
H
H
Me
Me
ZnII
HgII
2.9
0.5
33[a]
41[a]
disaccharide
10
10
13
13
19
19
Gal[b]
Gal
H
H
H
Me
Me
6Man
6Man
2Man
2Man
ZnII
HgII
ZnII
HgII
ZnII
HgII
1.3
0.5
2.1
0.5
2.0
0.5
37
42
30
35
4
1
Previously it had been demonstrated that the C4 popula-
tion of xylose in the presence of HgII was 17% in the case
of the trisaccharide 1 and 39% in that of the trisaccharide
Galb(1,3)Hinb(1,6)ManaMe (6).[7] The difference between
the bent-state stabilities of the two hinged trisaccharides 1
and 6 suggests that the bending ability is influenced by the
interaction between the reducing and nonreducing ends. In
this report we investigate the bending abilities of several
hinged di- and trisaccharides, to assess the compatibility be-
tween the two end sugars and ultimately to find a better
combination.
H
5
trisaccharide
Gal
1
1
6
6
23
23
2Man
2Man
6Man
6Man
2Man
2Man
ZnII
HgII
ZnII
HgII
ZnII
HgII
3.1
0.5
2.0
0.5
1.5
0.5
23[a]
17[a]
21[a]
39[a]
75
Gal
Gal
Gal
Man
Man
ꢁ75
[a] Data from reference [7]. [b] The abbreviations are as follows:
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H. Yuasa et al.
Scheme 2. The syntheses of hinged di- and trisaccharides: a) BF3·OEt2, MS (4 Š), CH2Cl2; b) NaOMe, MeOH; c) H2S, Py/H2O; d) TMSOTf, MS (4 Š),
CH2Cl2, ꢀ408C to RT; e) Na, liq. NH3/THF, RT.
First of all we examined the effects of Zn(OAc)2 and Hg-
(OAc)2 additions to the selected di- and trisaccharides (10,
13, 19, 23) in [D3]AcONa buffer (Table 1). As in the previ-
ous studies, the addition of the metal ions caused signal
unit. All the measurements were therefore performed at
temperatures between 70 and 808C, at which the signals
1
were sharp enough for J values to be read. H NMR spectra
of compound 23 in the absence and in the presence of Zn-
(OAc)2 are shown in Figure 1. The signal splittings of the
hinge sugar unit became smaller after the addition of Zn-
1
broadenings in the H NMR at 258C, due to the relatively
4
1
slow exchange between C1 and C4 structures of the hinge
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Improvement of the Bending Ability of a Hinged Trisaccharide
FULL PAPER
Table 2. Comparison of the bending abilities of the hinged mono-, di-,
and trisaccharides in terms of the reactivity toward the carbonylation of
the hinge unit.
Compd.
R1
R2
Product
Temp.
Time [h]
Yield [%]
monosaccharide
32
19
H
disaccharide
H
Me
33
34
RT
2
77[a]
46
2Man[b]
1208C
24
trisaccharide
Gal
1
6
17
23
31
2Man
6Man
6Man
2Man
6Gal
4
1208C
RT
RT
RT
RT
40
5
5
5
5
36[a]
87
86
75
68
Gal
Man
Man
Man
35
36
37
38
[a] Data from reference [8]. [b] The same abbreviations are used as those
in Table 1, except for the following:
Figure 1. 1H NMR spectra (400 MHz) of compound 23 (26 mm) in the ab-
sence and in the presence of Zn(OAc)2 (1.5 equiv) in [D3]AcONa buffer
(pH 7.0, 50 mm). a) 23 at 258C; b) 23 with Zn(OAc)2 at 808C.
the experiments with 0.5 equivalent HgII and about the
same degree of the bent population was obtained (ꢁ75%),
1
though the slight signal broadenings in the H NMR spec-
3
(OAc)2, as has been observed for the other hinge sugars.
Populations (%) of the C4 conformation were computed by
trum hampered the full conformation analysis by J values.
The chelation of the hinge sugars to ZnII and HgII was a re-
versible process, so the C4 populations reflect the thermo-
1
1
a multiple regression analysis with a least-squares fitting of
3
the J values calculated for model structures to the observed
dynamic stabilities of the bent conformation in water.
We next examined the N,N’-carbonylation of the hinged
di- and trisaccharides in DMF (Table 2). We had previously
reported that the carbonylation of the trisaccharide 1 was
sluggish and required harsh conditions relative to those used
for the monosaccharide 32. Similarly poor reactivity was ob-
served for the disaccharide 19: heating for 24 h afforded
only a 46% yield of the product 34. However, the trisacchar-
ides 6, 17, 23, and 31 showed as good a reactivity as the
monosaccharide 32 toward the carbonylation, with the reac-
tions proceeding in room temperature within 5 h and giving
70% to 90% yields of the products 35, 36, 37, and 38, re-
spectively. The carbonylated products 34–38 were isolated
and characterized by 1H and 13C NMR spectroscopy and
mass spectrometry.
3
ones. The calculated J values were derived by the general-
ized Karplus equation[10] from the dihedral angles of the
4
1
2
3
computed C1, C4, S0, S1, and 03B structures optimized with
PC Spartan Plus software (Wavefunction Inc.) by use of the
SYBYL force field. The populations of the skew and boat
conformations were negligible. As a result, the disaccharides
10 and 13, with nonreducing galactose (Gal) and with 6-O-
glycosylated mannose (6Man), respectively, at their reducing
ends, were comparable to the monosaccharide 32 and the
trisaccharide 6 with regard to their bending ability, and the
1
populations of the C4 conformations in the presence of a
metal ion were between 30% and 42% (Table 1). However,
a significant loss of bending ability was found in the case of
the disaccharide 19, with
a 2-O-glycosylated mannose
(2Man) at the reducing end: the addition of Zn(OAc)2 and
Hg(OAc)2 afforded only 4% and 5% C4 conformations of
Third, we examined PtII complexformation by the same
di- and trisaccharides as used for the carbonylation. The PtII
complexformations were carried out through the addition
of K2[PtCl4] to the buffered solutions of the hinged oligosac-
charides and were monitored through optical rotation
changes to calculate the first-order rate constants (Table 3).
Previously, the monosaccharide 32 and trisaccharide 1 had
shown similar reactivity toward PtII complexformation. In
this study, the PtII complexformation rate for the disacchar-
ide 19 was elucidated as about 50% of that of the trisacchar-
1
the hinge unit, respectively. In contrast, the bending ability
of the trisaccharide 23, with a nonreducing Man and a 2Man
at the reducing end, was overwhelmingly efficient: a 1C4
population of 75% was achieved when 1.5 equivalents of
1
ZnII were added, as shown by the H NMR spectral change
(Figure 1). The extended conformation of 23 was quickly re-
covered by the addition of 1.5 equivalents of triethylenetetr-
amine, a chelator of ZnII. The same trends were observed in
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H. Yuasa et al.
Table 3. Comparison of the bending abilities of the hinged mono-, di-,
and trisaccharides in terms of reactivity toward the complexation of the
hinge unit with PtII.
[a]
Compd
R1
R2
Product
Yield [%]
k [”10ꢀ4 sꢀ1
]
monosaccharide
32
19
H
disaccharide
H
Me
39
40
46[b]
43
1.30[b]
0.79
Figure 2. The predicted repulsive interactions in compound 34. The struc-
ture was minimized by use of PC Spartan Plus software (Wavefunction
Inc.) with the SYBYL force field, and the glycosidic torsion angles f and
y were manually varied. a) The distance between O3 and H5a’ is less
than 2.6 Š when f = 608 and y>21.58. b) The distance between H1 and
H1’ is less than 2.4 Š when f = 608 and y<15.58.
2Man[c]
trisaccharide
Gal
1
6
17
23
31
2Man
6Man
6Man
2Man
6Gal
5
46[b]
46
21
49
60
1.68[b]
1.11
1.15
1.17
1.23
Gal
Man
Man
Man
41
42
43
44
Since the trisaccharide 1 is the 3’-O-b-galactosylated de-
rivative of disaccharide 19, this trisaccharide is likely to
have as low a bending ability as its counterpart 19. Indeed,
the N,N’-carbonylation of 1 proceeded as slowly as that of
19. However, as has been demonstrated in previous papers,
all the chelation reactions of 1 were comparable to those of
the monosaccharide 32, showing a fair bending ability. The
better bending ability of the trisaccharide 1 than of the dis-
accharide 19 in the chelation reactions is explicable in terms
of an attractive interaction between Gal and 2Man, which
compensates for the repulsive interactions in the disacchar-
ide counterpart at the reducing end. Our previous NOESY
study on the conformation of the bent trisaccharide 4 re-
vealed a close contact of OH2’’ and O5,[8] suggesting hydro-
gen bonding between Gal and 2Man. This single hydrogen
bond is not strong enough to exceed the intrinsic bending
difficulty in the disaccharide counterpart, and this is perhaps
the reason why the bending ability of the trisaccharide 1 is
slightly less than that of the monosaccharide 32. The slug-
gish carbonylation of 1 may be due to weakening of the
single hydrogen bond in the polar DMF. The above explana-
tions are tentative, because the solvent polarity may influ-
ence both the interresidual conformations and the reactivity
of the hinge sugars through stereoelectronic effects. The
contradictory behaviors of the hinge sugars toward the three
bending processes will be uncovered only after thorough ex-
aminations are performed.
[a] First-order rate constants determined by optical rotation changes.
[b] Data from reference [8]. [c] The same abbreviations are used as in
Table 2.
ide 1. On the other hand, PtII complexformation by the tri-
saccharides 6, 17, 23, and 31 proceeded smoothly at rates
slightly slower than that of the monosaccharide 32. The PtII
complexproducts 40–44 were isolated and characterized by
1H and 13C NMR spectroscopy and mass spectrometry.
From the three bending processes of the hinge sugars, it is
now possible to discuss and anticipate the factors influencing
the bending abilities of the hinged oligosaccharides. Both
the nonreducing Gal and the 6Man and 6Gal at the reducing
ends have small influences on the bending abilities of the di-
and trisaccharides 10, 13, 6, 17, and 31. In particular, the ob-
servations for the trisaccharides 6, 17, and 31 were contrary
to our expectations that the two end sugars would clash with
each other to result in much less bent formations, suggesting
that there is neither attractive nor repulsive sugar–sugar in-
teraction when the trisaccharides 6, 17, and 31 are bent with
the assistance of the chelation. Perhaps the 6Man or 6Gal
ꢀ ꢀ
units can escape these interactions through C5 C 6 rota-
tion.
The disaccharide 19, with 2Man at the reducing end,
showed the weakest bending abilities for each of the three
reactions tested above. This low bending ability is attributa-
ble to the constrained structure of the bent state, as illustrat-
ed by the carbonylated derivative 34 (Figure 2). If we
assume the usual exo anomeric torsion angle (608)[11] for
O5’-C1’-O-C2 (f) of 34, the stress-free range for another
glycosidic torsion angle, H2-C2-O-C1’ (y), is extremely
small, between 15.58 and 21.58, as demonstrated by manual
variation of the torsion angle of the minimized structure on
computer. For y with more than 21.58 and less than 15.58,
the H1’–H1 and H5a’–O3 distances are less than 2.4 Š and
2.6 Š, respectively, each within the van der Waals distance.
Therefore, the bending process accompanies a loss in the
freedom of motion to a great extent.
The trisaccharide 23 bent very efficiently in the presence
1
of ZnII or HgII. The C4 population of 75% is much larger
than those of all the other hinged trisaccharides ever tested
(<40%). Moreover, the extended conformation of 23 was
completely recovered through the addition of triethylene-
tetramine, so we have improved the efficiency of a stretch–
bent switch of a hinged trisaccharide to a great extent. This
result indicates that the bent conformation of 23 is thermo-
dynamically more stable than the extended conformation in
the presence of metal ions. The rapid and perfect bend for-
mation has been demonstrated with a dipyrene derivative of
hinge sugar, in which the bent structure was assisted by p–p
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Improvement of the Bending Ability of a Hinged Trisaccharide
FULL PAPER
in stabilizing the Man–2Man
stacking are another potential
driving force.
In contrast to the ZnII and
HgII chelation reactions, the
carbonylation and PtII complex
formation of 23 proceeded at
nearly the same rates as those
of the monosaccharide 32. Both
the carbonylation and the PtII
complexformation are irrever-
sible and first-order reactions,
and the cyclization through the
ꢀ
second N C or N–metal bond
Figure 3. Selected signals from the 2D HMQC-NOESY spectrum of the compound 37. The contours for posi-
tive and negative signals are represented by solid and dotted lines, respectively. The ordinates and abscissas formation is rate-determining.[8]
1
scale the chemical shifts in d (ppm) for 13C and H NMR, respectively. a) HMQC signals for H1’’/C1’’, H1’/C1’,
The reactivity is thus deter-
mined both by the nucleophilic-
ity of the second amino group
and H1/C1; b) NOESY signals for H1’’/H3’; c) NOESY signals for H-1’’/H-4’ and H-1’’/H-2’; d) NOESY signals
for H-1’/H-2.
undergoing the cyclization and
1
stacking of the pyrene groups.[9] It is therefore obvious that
Man and 2Man in 23 have an attractive interaction. Al-
though we found no NOE cross-peaks between the nonre-
ducing and reducing ends of the bent trisaccharide 37 in a
2D HMQC-NOESY experiment (Figure 3), NOEs for H-1’’/
H-3’, H-1’’/H-4’, and H-1’/H-2 were observed. We also car-
ried out an AMBER* conformation search for 37 by gener-
ating the various conformations by the Monte-Carlo
method, in which the distances between NOE hydrogen
atoms are restricted to 1.5 to 2.0 Š. The simulation found
ten stable conformations within 2.0 kcalmolꢀ1 of the lowest
conformational energy. The most stable conformer was
found three times and has (f, y) of (80.7, ꢀ35.8) and
(ꢀ76.7, 1.3) for the nonreducing and reducing glycosidic
bonds, respectively, while the other nine stable conformers
have similar (f, y) angles. These results provide support for
the U-shape structure of 37, in which the 3OH’’ and 6C of
the mannose residues point upward and their hydrophobic
faces are almost in parallel (Figure 4). Although these
by the stability of the C4 conformation (i.e., the effective
concentration of the reactive species). The effective concen-
tration of the cyclizing amino group of 23 in water, on the
basis of the C4 populations in the presence of ZnII, is twice
1
that of 32. Therefore, in the case of the PtII complexforma-
tions, the nucleophilicity of the cyclizing amino group is
lower for 23 than for 32, probably due to steric repulsion be-
tween the nonreducing Man and PtII. This was also the case
for the carbonylation, and the low nucleophilicity of the
second amino group of 23 resulted in the same rate of car-
bonylation as for 32.
If the compatibilities of the two end sugars are responsi-
ble for the bending abilities of the hinged trisaccharides, this
relationship should also hold in the trisaccharide counter-
parts of longer oligosaccharides. To find the best combina-
tion of the reducing and nonreducing ends, we investigated
the bending abilities of various hinged trisaccharides. As a
result, we found that the bent structure of the trisaccharide
23 was more stable than the extended structure in the pres-
ence of ZnII or HgII, despite the apparent crowdedness. This
trisaccharide counterpart should therefore be an important
component of functional oligosaccharides.
The above discussions relate closely to specific sugar–
sugar interactions[12] such as LeX–LeX[13] and GM3–Gg3,[14]
through which cell–cell adhesion is mediated. These interac-
tions usually require CaII to “glue” the sugars strongly with
ionic bonds, but the specificity of the binding obviously orig-
inates from the integrated weak interactions such as hydro-
gen bonds and hydrophobic contacts between the sugars.
Furthermore, (KDN)GM3–Gg3 interaction does not require
CaII in the binding of rainbow trout sperm to egg,[15] so the
understanding of these sugar–sugar interactions is becoming
increasingly important.[16] However, these interactions are
too weak to be investigated as thoroughly as sugar–protein
or sugar–DNA interactions. Polyvalent or tethered model
systems have therefore been employed for the studies of
sugar–sugar interactions.[17] Our hinged trisaccharides are
different from polyvalent or tethered model systems in that
Figure 4. The global minimum conformation of the N,N’-carbonylated tri-
saccharide 37 from NOEs and the conformation search.
model structures exhibited no hydrogen bonds between
Man and 2Man, the possibility of hydrogen bonding-assisted
bending could not be abandoned. The hydrophobic effects
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H. Yuasa et al.
were performed under dry argon with use of syringes. Thin-layer chroma-
tograms (TLCs) were performed on precoated silica gel Merck 60-F254
plates (Art 5715) and visualized by quenching of fluorescence and/or by
charring after spraying with CeSO4 (1%)/(NH4)6Mo7O24·4H2O (1.5%)/
H2SO4 (10%). Column chromatography was performed on Merck Kiesel-
gel 60 (Art 7734), Wako gel C-300, or Kanto Silica gel 60N (spherical,
neutral) with the solvent systems specified. Optical rotations were deter-
mined with a Horiba SEPA-200 or a JASCO DIP-4 polarimeter in 1 dm
or 0.1 dm length cells. 1H NMR (1D, COSY, HMQC, and HMBC) spec-
tra were recorded at 400 MHz (Varian Unity-400) or 270 MHz (JEOL
EX-270). Internal tetramethylsilane (d = 0 ppm) was used as a standard
in CDCl3, or solvent peaks were used as standards. Chemical shifts are
expressed in ppm referenced to the solvent as an internal standard. The
multiplicities of signals are abbreviated as follows: s = singlet, d = dou-
blet, dd = doublet of doublets, t = triplet, dt = doublet of triplets, ddd
= doublet of doublets of doublets, br = broad signal, m = multiplet. 13C
NMR spectra were recorded at 67.8 MHz (JEOL JNM-EX-270) or
two sugars are forced into contact with each other with the
assistance of chelation, so the very weak interactions, usual-
ly unmeasurable, might be evaluated with this system,
whereas the interactions between large oligosaccharides will
still be difficult.
This study is also relevant to molecular switches.[18] When
a certain signal, such as a small molecule or light, is applied
to a molecular switch, the switchꢁs conformation changes
concomitantly with certain of its physical properties, such as
conductivity and fluorescence. Though the hinge trisacchar-
ide 23 does not generate any striking physical property
changes in its current form, it might serve as part of a mo-
lecular switch if appropriate components were attached, as
has been demonstrated by the hinge-based metal ion
sensor,[9] conformational changes in which generate an exci-
mer fluorescence with the addition of a metal ion.
100.6 MHz (Varian Unity-400) and a solvent peak (d
= 77.0 ppm of
CDCl3) or acetone (d = 30.89 ppm in D2O) was used as a standard.
High-resolution mass spectra (HRMS) were recorded on a Mariner Bio-
spectrometry Workstation ESI-TOF MS.
NOE study: For the NOE study, the trisaccharide 37 (15 mg) was dis-
solved in D2O (0.3 mL) and examined in a Bruker AVANCE 400 instru-
ment. The sample was set to 298 K. Two-dimensional 1H–13C HMQC,
HMQC-TOCSY, and HMQC-NOESY spectra were measured by use of
pulse programs in the Bruker standard library (invbtp, invbmltp, and in-
vbnotp, respectively). During acquisition, GARP decoupling was per-
formed toward 13C (F1 dimension). For HMQC-TOCSY experiments, the
MLEV-17 pulse sequence was used and its mixing time was varied from
20 ms to 80 ms. For HMQC-NOESY experiments, the mixing time was
also varied (100 ms to 800 ms). A total of 256 t1 data points were collect-
ed with 64 transients per t1. The data were transformed as a 2 K and 1 K
matrix.
Conclusion
Hinge
sugars—2,4-diamino-2,4-dideoxy-b-d-xylopyrano-
sides—are potential components for molecular devices,
since the C1–1C4 conformational change induced by chela-
4
tion of the diamino group with a metal ion generates a tran-
sition between the extended and bent conformations with
regard to the 1-O- and 3-O-substituents. In previous studies
the conformational change of the hinge sugar has been un-
1
satisfactory, giving at most 40% C4 population. One excep-
Computational methods: Molecular mechanics calculations were per-
formed with MacroModel 5.5[20] and the force field used was AMBER*.
Conformational analysis of the trisaccharide 37 was performed in GB/SA
water[21] by a Monte-Carlo procedure. We searched for the lowest-energy
conformations satisfying two distances (H-1’/H2, H1’’/H3’ and H1’’/H4’)
tion was the 1,3-di-O-pyrenylmethyl hinge sugar, which per-
mitted nearly a 100% 1C4 population in the presence of
ZnII, probably because a p–p stacking of the pyrene groups
assists the bent structure formation. This study has demon-
strated the presence of sugar–sugar attractive interactions
that assist the formation of bent trisaccharides. To this end
we have examined three hinged disaccharides and five
hinged trisaccharides for their bending abilities in terms of
1C4 populations in the presence of ZnII or HgII, reactivity
toward an N,N’-carbonylation to afford the locked bent
structures, and/or rates of chelation to PtII. The bending
ability of a hinged disaccharide—Hinb(1,2)ManaMe—was
within 1.5–2 Š as suggested by NOE experiments. These distance con-
ꢀ2
straints were applied with the force constant of 250 kJmolꢀ1
Š
.
The Monte-Carlo search was conducted with a total of 10000 search
steps with use of TNCG minimization to gradient convergence
(<0.05 kJmolꢀ1). A total of 2539 unique conformations were saved. The
lowest-energy conformer was found three times and there were nine ad-
ditional conformers within 2.0 kcalmolꢀ1. The lowest-energy conformer is
shown in Figure 4.
Methyl (2,3,4,6-tetra-O-acetyl-b-d-galactopyranosyl)-(1!3)-2,4-diazido-
2,4-dideoxy-3-O-b-d-xylopyranoside (9): A solution of 2,3,4,6-tetra-O-
acetyl-b-d-galactopyranosyl trichloroacetimidate (7; 2.634 g, 5.35 mmol)
in dichloromethane (15 mL) was slowly added at ꢀ758C to a stirred mix-
ture of methyl 2,4-diazido-2,4-dideoxy-3-O-b-d-xylopyranoside (8;
712 mg, 3.32 mmol), BF3·OEt2 (100 mL, 813 mmol), and molecular sieves
(4 Š, 0.80 g) in dichloromethane (15 mL). The temperature was allowed
to increase slowly to room temperature over 2 h. After the addition of
triethylamine (200 mL, 1.44 mmol), the mixture was evaporated and chro-
matographed on silica gel (hexane/ethyl acetate 2:1) to give 9 (1.715 g,
95%) as a foam: Rf = 0.29 (hexane/ethyl acetate 2:1); [a]2D5 = +8.3 (c
= 1.23 in CHCl3); 1H NMR (400 MHz, CDCl3, 258C, TMS): d = 5.38
1
very low: it afforded at most a 5% C4 population in the
presence of a metal ion, required harsh conditions to bridge
the diamino group with a carbonyl group, and underwent a
sluggish chelation to PtII. However, the hinged trisaccharide
Mana(1,3)Hinb(1,2)ManaMe with the common reducing
disaccharide had a bending ability better than that of the
hinge monosaccharide, affording a bent population of 75%
in the presence of ZnII. This high 1C4 population should
extend the scope for using the hinged trisaccharide in mo-
lecular devices and functional polysaccharides.
3
3
3
3
(dd, J3,4 = 3.5, J4,5 = 1.0 Hz, 1H; H4’), 5.23 (dd, J1,2 = 7.9, J2,3
=
3
10.5 Hz, 1H; H2’), 5.04 (dd, 1H; H3’), 4.85 (d, 1H; H1’), 4.23 (dd, J5,6a
= 6.3, J6a,6b = 11.1 Hz, 1H; H6a’), 4.11 (dd, J5,6b = 7.2 Hz, 1H; H6b’),
4.09 (d, J1,2 = 7.9 Hz, 1H; H-1), 3.97 (dd, J4,5a = 5.5, J5a,5b = 12.1 Hz,
2
3
3
3
2
3
1H; H5a), 3.93 (ddd, 1H; H5’), 3.54 (s, 3H; OCH3), 3.52 (ddd, J3,4
=
3
3
Experimental Section
9.3, J4,5b = 10.7 Hz, 1H; H4), 3.43 (dd, J2,3 = 9.6 Hz, 1H; H3), 3.24
(dd, 1H; H2), 3.04 (dd, 1H; H5b), 2.13, 2.10, 2.04, 1.99 (4”s, 3H each;
COCH3) ppm; 13C NMR (67.8 MHz, CDCl3, 258C): d = 170.3, 170.3,
170.1, 169.5 (CH3CO), 103.6, 101.1 (C1, C1’), 80.0, 70.9, 70.5, 69.0, 66.8,
66.0, 63.9, 61.0, 59.5, 57.1 (C2, C3, C4, C5, C2’, C3’, C4’, C5’, C6’, OCH3),
General: All solvents and reagents used were reagent grade and, in cases
in which further purification was required, standard procedures[19] were
followed. Solution transfers when anhydrous conditions were required
6484
www.chemeurj.org
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2005, 11, 6478 – 6490

Improvement of the Bending Ability of a Hinged Trisaccharide
FULL PAPER
3
20.7, 20.6, 20.5 (CH3CO) ppm; elemental analysis calcd (%) for
C20H28N6O12 (544.5): C 44.12, H 5.18, N 15.44; found: C 44.09, H 5.19, N
15.18.
3.2 Hz, 1H; H2), 4.35 (dd, J5,6b = 5.9 Hz, 1H; H6b), 4.27–4.13 (m, 4H;
3
H3, H4, H5, H3’), 4.02 (dd, J4,5b = 7.3 Hz, 1H; H5b’), 3.90 (s, 3H;
OCH3), 3.73 (m, 1H; H4’), 3.61 (brt, 3J = 6 Hz, 1H; H2’), 2.39 ppm (s,
3H; HgOCOCH3).
Methyl (b-d-galactopyranosyl)-(1!3)-2,4-diamino-2,4-dideoxy-3-O-b-d-
xylopyranoside (10): A solution of 9 (1.542 g, 2.83 mmol) in NaOMe
(50 mm, 20 mL) was kept at room temperature for 4 h. The mixture was
evaporated and chromatographed on silica gel (ethyl acetate/MeOH
20:1) to give a product (815 mg) with an Rf value of 0.26 (ethyl acetate/
MeOH 20:1). The product was dissolved in pyridine/H2O (1:1, 50 mL),
and H2S gas was bubbled for 10 min at 08C. The solution was kept for
15 h, evaporated, and chromatographed on spherical silica gel (iPrOH/
H2O/28% NH3 8:1:1) to give 10 (638 mg, 69%) as white solid: Rf = 0.47
(iPrOH/H2O/28% NH3 7:3:1); m.p. 2358C (decomp); [a]2D4 = ꢀ26.2 (c =
Compound 13 (32 mm)
+
2.1 equiv Zn(OAc)2: 1H NMR (400 MHz,
50 mm [D3]AcONa buffer, 808C, DOH): d = 5.30 (brs, 1H; H1), 5.18 (d,
3J1,2 = 5.6 Hz, 1H; H1’), 4.75 (m, 1H; H5a’), 4.66 (d, J5,6a = 11.4 Hz,
3
3
3
3
1H; H6a), 4.50 (dd, J1,2 = 1.9, J2,3 = 3.2 Hz, 1H; H2), 4.41 (dd, J5,6b
=
3
5.5 Hz, 1H; H6b), 4.33–4.22 (m, 4H; H3, H4, H5, H3’), 4.06 (dd, J4,5b
=
2
7.8, J5a,5b = 12.2 Hz, 1H; H5b’), 3.97 (s, 3H; OCH3), 3.61 (br, 1H; H4’),
3.48 (br, 1H; H2’), 2.50 ppm (s, 12.6H; ZnOCOCH3).
Methyl (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-
diazido-2,4-dideoxy-b-d-xylopyranosyl)-(1!6)-2,3,6-tri-O-benzyl-a-d-
mannopyranoside (14): A mixture of 12 (280 mg, 433 mmol) and crushed
MS (4 Š, 600 mg) in CH2Cl2 (8 mL) was stirred under Ar for 1 h and
cooled at ꢀ408C. TMSOTf (14.5 mL, 80 mmol) in CH2Cl2 (145 mL), and
then a solution of 2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl tri-
chloroacetimidate (11; 392 mg, 615 mmol) in CH2Cl2 (3 mL) were slowly
added to the mixture. The temperature was allowed to increase slowly to
room temperature over 2 h and the mixture was stirred for a further
30 min at room temperature. The reaction was quenched by addition of
triethylamine (22 mL, 158 mmol). The insoluble material was removed by
celite filtration and the filtrate was evaporated and chromatographed on
a column of silica gel (toluene/ethyl acetate 20:1 to 8:1) to give trisac-
charide 14 (446 mg, 92%) as a syrup: Rf = 0.30 (toluene/ethyl acetate
1.03 in H2O); 1H NMR (400 MHz, D2O, 70 8C, DOH): d
= 5.00 (d,
3
3
3J1,2 = 7.6 Hz, 1H; H1’), 4.71 (d, J1,2 = 8.1 Hz, 1H; H1), 4.47 (dd, J4,5a
2
3
= 5.3, J5a,5b = 11.9 Hz, 1H; H5a), 4.42 (d, J3,4 = 3.4 Hz, 1H; H4’), 4.27
(dd, J5,6a = 7.5, J6a,6b = 12.0 Hz, 1H; H6a’), 4.24 (dd, J5,6b = 4.6 Hz,
1H; H6b’), 4.18 (dd, 1H; H5’), 4.15 (dd, J2,3 = 9.8 Hz, 1H; H3’), 4.07
3
2
3
3
3
3
(dd, 1H; H2’), 4.02 (s, 3H; OCH3), 3.88 (dd, J2,3 = 9.6, J3,4 = 9.5 Hz,
1H; H3), 3.75 (dd, J4,5b = 10.8 Hz, 1H; H5b), 3.40 (ddd, 1H; H4), 3.23
(dd, 1H; H2) ppm; 13C NMR (67.8 MHz, D2O, 25 8C, acetone): d
=
104.8, 104.2 (C1, C1’), 86.9, 75.4, 72.8, 71.3, 68.6, 66.1, 61.0, 57.4, 56.4,
50.5 (C2, C3, C4, C5, C6, C2’, C3’, C4’, C5’, OCH3) ppm; HRMS (ESI):
calcd for C12H25N2O8 [M+H]+: 325.1611; found 325.1624.
Compound 10 (14 mm)
+
0.5 equiv Hg(OAc)2: 1H NMR (400 MHz,
3
8:1); [a]2D4
=
+30.9 (c = 1.01 in CHCl3); 1H NMR (400 MHz, CDCl3,
50 mm [D3]AcONa buffer, 808C, DOH): d = 5.15 (d, J1,2 = 6.7 Hz, 1H;
3
H1’), 5.07 (d, J1,2 = 5.2 Hz, 1H; H1), 4.78 (m, 1H; H5a), 4.52 (m, 1H;
258C, TMS): d = 7.37–7.15 (m, 30H; Ph”6), 5.42 (brs, 1H; H2’’), 5.27
3
H4’), 4.39–4.36(m, 3H; H3, H6a’, H6b’), 4.30 (m, 1H; H5’), 4.24 (dd,
(d, J1,2 = 1.7 Hz, 1H; H1’’), 4.98–4.46 (m, 13H; CH2Ph”6, H1), 4.23 (d,
3
3
3J2,3 = 9.9, J3,4 = 3.4 Hz, 1H; H3’), 4.17 (dd, 1H; H2’), 4.11 (dd, J4,5b
=
3J1,2 = 7.5 Hz, 1H; H1’), 4.11–3.75 (m, 11H; H2, H3, H4, H5, H6a, H6b,
2
3
3
2
6.9, J5a,5b = 12.4 Hz, 1H; H5b), 4.10 (s, 3H; OCH3), 3.99 (ddd, J3,4
6.7, J4,5a = 4.0 Hz, 1H; H4), 3.76 (t, 1H; H2), 2.45 ppm (s, 3H; HgO-
=
H5a’, H3’’, H4’’, H5’’, H6a’’), 3.71 (dd, J5,6b = 1.5, J6a,6b = 10.7 Hz, 1H;
3
3
3
3
H6b’’), 3.49 (ddd, J3,4 = 9.2, J4,5a = 5.3, J4,5b = 10.7 Hz, 1H; H4’), 3.33
3
COCH3).
(t, J2,3 = 9.6 Hz, 1H; H3’), 3.31 (s, 3H; OCH3), 3.26 (dd, 1H; H2’), 3.08
2
(t, J5a,5b = 11.6 Hz, 1H; H5b’), 2.15 (s, 3H; COCH3) ppm; 13C NMR
Compound 10 (24 mm)
+
1.25 equiv Zn(OAc)2: 1H NMR (400 MHz,
3
(100.6 MHz, CDCl3, 258C): d = 170.4 (C=O), 138.5, 138.4, 138.3, 138.0,
128.35, 128.3, 128.25, 128.2, 128.0, 127.85, 127.8, 127.7, 127.65, 127.6,
127.55, 127.5, (Ph”6), 103.1 (C1’), 99.1 (C1), 98.9 (C1’’), 80.3, 77.9, 75.0,
74.4, 74.0, 72.4, 71.4 (C2, C3, C4, C5, C3’’, C4’’, C5’’), 79.5 (C3’), 75.1,
74.9, 73.4, 72.7, 72.0, 71.9 (CH2Ph”6), 69.3 (C6), 69.0 (C2’’), 68.5 (C6’’),
65.3 (C2’), 63.5 (C5’), 61.3 (C4’), 54.7 (OCH3), 21.1 (CH3CO) ppm;
HRMS (ESI): calcd for C62H68N6O14Na [M+Na]+: 1143.4691; found
1143.4686; elemental analysis calcd (%) for C62H68N6O14·3/2H2O
(1148.3): C 64.85, H 6.23, N 7.32; found: C 64.77, H 5.89, N 7.64.
50 mm [D3]AcONa buffer, 808C, DOH): d = 5.11 (d, J1,2 = 7.6 Hz, 1H;
3
H1’), 5.06 (d, J1,2 = 5.6 Hz, 1H; H1), 4.78 (m, 1H; H5a), 4.52 (dd,
3
3
3J3,4 = 2.0, J4,5 = 1.1 Hz, 1H; H4’), 4.38 (t, J = 6.5 Hz, 1H; H3), 4.37–
3
4.35 (m, 2H; H6a’, H6b’), 4.24 (dd, J2,3 = 10.1 Hz, 1H; H3’), 4.17 (dd,
3J2,3 = 9.9 Hz, 1H; H2’), 4.11 (dd, J4,5b = 7.3, J5a,5b = 12.4 Hz, 1H;
3
3
3
H5b), 4.09 (s, 3H; OCH3), 3.91 (dt, J4,5a = 4.0 Hz, 1H; H4), 3.67 (brt,
1H; H2), 2.50 ppm (s, 7.5H; ZnOCOCH3).
Methyl (2,4-diamino-2,4-dideoxy-b-d-xylopyranosyl)-(1!6)-a-d-manno-
pyranoside (13): H2S gas was bubbled at 08C for 10 min into a solution
of methyl (2,4-diazido-2,4-dideoxy-b-d-xylopyranosyl)-(1!6)-a-d-manno-
pyranoside (12; 464 mg, 710 mmol) in pyridine/H2O (1:1, 20 mL). The
mixture was kept at room temperature for 12 h, evaporated, and chroma-
tographed on silica gel (CHCl3/MeOH/H2O 3:1:0, then 65:35:6) to give a
product with an Rf value of 0.35 (CHCl3/MeOH/H2O 65:35:6). The prod-
uct was dissolved in liquid ammonia (ca. 20 mL) and sodium was added
to the solution in small portions at ꢀ788C until a blue color of the solu-
tion was maintained for more than 10 min. After addition of ethanol, the
solution was carefully evaporated and chromatographed on spherical
silica gel (iPrOH/H2O/28% NH3 8:1:1, then 7:3:1) to give 13 (127 mg,
55%) as a white solid: Rf = 0.37 (iPrOH/H2O/28% NH3 7:3:1); m.p.
Methyl (3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-diazido-2,4-
dideoxy-b-d-xylopyranosyl)-(1!6)-3,4,6-tri-O-benzyl-a-d-mannopyrano-
side (15): A solution of NaOMe in MeOH (50 mm, 6 mL) was added to a
stirred solution of 14 (446 mg, 398 mmol) in CH2Cl2 (2 mL). After 9 h, the
reaction mixture was evaporated and chromatographed on a column of
silica gel (hexane/ethyl acetate 2:1) to give 15 (253 mg, 59%) as a syrup:
Rf
= = +34.1 (c = 0.94 in
0.22 (hexane/ethyl acetate 2:1), [a]D25
CHCl3); 1H NMR (400 MHz, CDCl3, 258C, TMS): d = 7.37–7.16 (m,
3
30H; Ph”6), 5.28 (d, J1,2
= 1.5 Hz, 1H; H1’’), 4.98–4.48 (m, 13H;
3
CH2Ph”6, H1), 4.25 (d, J1,2 = 7.8 Hz, 1H; H1’), 4.12–3.68 (m, 13H; H2,
H3, H4, H5, H6a, H6b, H5a’, H2’’, H3’’, H4’’, H5’’, H6a’’, H6b’’), 3.47
3
3
3
3
1
116–1188C; [a]2D5 = +10.5 (c = 1.52 in H2O); H NMR (400 MHz, D2O,
(ddd, J3,4 = 9.3, J4,5a = 5.3, J4,5b = 10.8 Hz, 1H; H4’), 3.35 (t, J2,3
=
2
3
3
9.6 Hz, 1H; H3’), 3.31 (s, 3H; OCH3), 3.26 (dd, 1H; H2’), 3.08 (t, J5a,5b
= 11.6 Hz, 1H; H5b’), 2.54 (brs, 1H; OH) ppm; 13C NMR (100.6 MHz,
CDCl3, 258C): d
808C, DOH): d
=
5.31 (d, J1,2
=
1.4 Hz, 1H; H1), 4.90 (d, J1,2
=
3
2
8.1 Hz, 1H; H1’), 4.69 (dd, J5,6a = 1.8, J6a,6b = 11.4 Hz, 1H; H6a), 4.52
(dd, J4,5a = 11.8 Hz, 1H; H5a’), 4.50 (dd, J2,3 = 3.1 Hz, 1H; H2), 4.42
(dd, J5,6b = 5.3 Hz, 1H; H6b), 4.35–4.24 (m, 3H; H4, H5), 3.98 (s, 3H;
OCH3), 3.82 (dd, J4,5b = 10.8 Hz, 1H; H5b’), 3.76 (dd, J2,3 = 9.8, J3,4
3
3
= 138.45, 138.4, 138.35, 138.3, 138.25, 137.9, 128.4,
3
128.35, 128.3, 128.25, 128.2, 127.9, 127.85, 127.8, 127.75, 127.7, 127.6,
127.5, 127.4 (Ph”6), 103.1 (C1’), 100.5 (C1’’), 99.0 (C1), 79.2 (C3’), 80.3,
79.8, 75.0, 74.4, 73.9, 72.0, 71.4 (C2, C3, C4, C5, C3’’, C4’’, C5’’), 75.0,
74.9, 73.4, 72.7, 72.0 (CH2Ph”6), 69.3 (C6), 68.6 (C2’’), 68.5 (C6’’), 65.3
(C2’), 63.4 (C5’), 61.5 (C4’), 54.7 (OCH3) ppm; HRMS (ESI): calcd for
C60H66N6O13 Na [M+Na]+: 1101.4586; found 1101.4585; elemental analy-
sis calcd (%) for C60H66N6O13·H2O (1097.2): C 65.68, H 6.25, N 7.66;
found: C 65.39, H 6.02, N 7.31.
3
3
3
=
9.6 Hz, 1H; H3’), 3.37 (ddd, 1H; H4’), 3.19 (dd, 1H; H2’) ppm; 13C NMR
(67.8 MHz, D2O, 25 8C, acetone): d = 103.8, 100.2 (C1, C1’), 75.3, 70.6,
69.7, 69.0, 68.2, 65.7, 65.4, 56.0, 54.1, 51.1 (C2, C3, C4, C5, C6, C2’, C3’,
C4’, C5’, OCH3) ppm; HRMS (ESI): calcd for C12H25N2O8 [M+H]+:
325.1611; found 325.1598.
Compound 13 (34 mm)
50 mm [D3]AcONa buffer, 708C, DOH): d = 5.24 (brs, 1H; H1), 5.14 (d,
+
0.5 equiv Hg(OAc)2: 1H NMR (400 MHz,
Methyl (3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-
dideoxy-b-d-xylopyranosyl)-(1!6)-2,3,4-tri-O-benzyl-a-d-mannopyrano-
side (16): Ar gas was bubbled at 08C for 20 min into a solution of 15
3
2
3J1,2 = 5.5 Hz, 1H; H1’), 4.71 (dd, J4,5a = 4.0 Hz, J5a,5b = 12.1 Hz, 1H;
2
3
3
H5a’), 4.60 (d, J6a,6b = 11.3 Hz, 1H; H6a), 4.43 (dd, J1,2 = 1.7, J2,3
=
Chem. Eur. J. 2005, 11, 6478 – 6490
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
6485

H. Yuasa et al.
(369 mg, 342 mmol) in pyridine/H2O (10:1, 15.4 mL), followed by H2S gas
for 10 min. The mixture was kept at room temperature for 12 h. After
the mixture had been evaporated, the residue was taken up with metha-
nol, and the insoluble material was removed by celite filtration. The fil-
trate was evaporated and chromatographed on silica gel (CHCl3/MeOH
(67.8 MHz, D2O, 25 8C, acetone): d = 100.2, 98.6 (C1, C1’), 76.5, 72.5,
71.6, 69.4, 66.8, 63.5, 60.4, 56.1, 54.9, 51.7 (C2, C3, C4, C5, C6, C2’, C3’,
C4’, C5’, OCH3) ppm; HRMS (ESI): calcd for C12H25N2O8 [M+H]+:
325.1611; found 325.1607.
Compound 19 (29 mm)
+
0.5 equiv Hg(OAc)2: 1H NMR (400 MHz,
20:1) to give 16 (291 mg, 83%) as an amorphous solid; Rf
(CHCl3/MeOH 10:1); [a]2D5 +41.5 (c = 1.01 in CHCl3); 1H NMR
(400 MHz, CDCl3, 258C, TMS): d = 7.47–7.17 (m, 30H; Ph”6), 5.10 (d,
= 0.27
50 mm [D3]AcONa buffer, 708C, DOH): d = 5.16 (s, 1H; H1), 5.01 (d,
3
2
3J1,2 = 7.8 Hz, 1H; H1’), 4.54 (dd, J4,5a = 5.0, J5a,5b = 11.9 Hz, 1H;
H5a’), 4.40 (m, 1H; H2), 4.17–4.07 (3H; H3; H6a, H6b), 4.07 (t, 3J =
9.4 Hz, 1H; H3’), 3.97 (t, 3J = 9.6 Hz, 1H; H4), 3.90 (m, 1H; H5), 3.85
=
3
3J1,2 = 2.9 Hz, 1H; H1’’), 4.92–4.43 (m, 12H; CH2Ph”6), 4.74 (d, J1,2
=
3
1.8 Hz, 1H; H1), 4.13–4.08 (m, 2H; H6a, H1’), 4.04 (q, 1H; H5’’), 3.99 (t,
3J2,3 = 3.1 Hz, 1H; H2’’), 3.90–3.72 (m, 8H; H2, H3, H4, H5, H6a, H5a’,
H3’’, H4’’), 3.69–3.60 (m, 2H; H6a’’, H6b’’), 3.27 (s, 3H; OCH3), 3.12 (t,
(dd, J4,5b = 10.4 Hz, 1H; H5b’), 3.70 (s, 3H; OCH3), 3.64 (ddd, 1H;
H4’), 3.44 (dd, 1H; H2’), 2.24 ppm (s, 3H; HgOCOCH3).
Compound 19 (29 mm)
50 mm [D3]AcONa buffer, 708C, DOH): d = 5.34 (brs, 1H; H1), 5.14 (d,
+
2.0 equiv Zn(OAc)2: 1H NMR (400 MHz,
3
2
3J2,3
=
3J3,4 = 9.3 Hz, 1H; H3’), 3.01 (t, J4,5b = 11.0, J5a,5b = 11.1 Hz,
3
3
1H; H5b’), 2.85 (ddd, J4,5a = 5.0 Hz, 1H; H4’), 2.75 (dd, J1,2 = 7.9 Hz,
1H; H2’) ppm; 13C NMR (100.6 MHz, CDCl3, 258C): d = 138.4, 138.3,
138.1, 138.05, 138.0, 137.9, 128.4, 128.25, 128.2, 128.15, 127.85, 127.8,
127.75, 127.7, 127.65, 127.6, 127.55, 127.5, 127.45, 127.4 (Ph”6), 105.5
(C1’), 101.0 (C1’’), 98.6 (C1), 87.8 (C3’), 80.0, 78.9, 75.0, 74.6, 74.4, 72.1,
71.3 (C2, C3, C4, C5, C3’’, C4’’, C5’’), 74.8, 74.2, 73.2, 72.4, 72.2, 71.9
(CH2Ph”6), 69.3 (C2’’), 69.2 (C6’’), 69.0 (C6), 67.3 (C5’), 56.2 (C2’), 54.6
(OCH3), 52.1 (C4’) ppm; HRMS (ESI): calcd for C60H71N2O13 [M+H]+:
1027.4956; found 1027.4951; elemental analysis calcd (%) for
C60H70N2O13·H2O (1045.2): C 68.95, H 6.94, N 2.68; found: C 69.17, H
6.86, N 2.79.
3
2
3J1,2 = 7.8 Hz, 1H; H1’), 4.70 (dd, J4,5a = 5.0, J5a,5b = 11.9 Hz, 1H;
3
3
H5a’), 4.58 (dd, J1,2 = 1.8, J2,3 = 3.5 Hz, 1H; H2), 4.37–4.25 (m, 3H;
H3, H6a, H6b), 4.18 (t, J = 9.6 Hz, 1H; H3’), 4.15 (t, J = 9.9 Hz, 1H;
H4), 4.08 (ddd, J5,6a = 2.4, J5,6b = 4.9 Hz, 1H; H5), 4.00 (t, J5,6b
3
3
3
3
3
=
10.4 Hz, H5b’), 3.90 (s, 3H; OCH3), 3.75 (dt, 1H; H4’), 3.54 (t, 1H; H2’),
2.42 ppm (s, 12H; ZnOCOCH3).
Methyl (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-
diazido-2,4-dideoxy-b-d-xylopyranosyl)-(1!2)-2,3,6-tri-O-benzyl-a-d-
mannopyranoside (20): A mixture of 18 (79 mg, 122 mmol) and crushed
MS (4 Š; 130 mg) in CH2Cl2 (4.5 mL) was stirred under Ar for 1 h and
cooled at ꢀ408C. TMSOTf (3.3 mL, 18.2 mmmol) in CH2Cl2 (33 mL), and
then a solution of 11 (87 mg, 137 mmol) in CH2Cl2 (870 mL) were slowly
added to the mixture. The temperature was allowed to increase slowly to
room temperature over 2 h, and the mixture was stirred for a further
30 min at room temperature. The reaction was quenched by addition of
triethylamine (5 mL, 36 mmol). The insoluble material was removed by
celite filtration and the filtrate was evaporated and chromatographed on
a column of silica gel (hexane/ethyl acetate 3:1 to 2:1) to give trisacchar-
Methyl (a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-dideoxy-b-d-xylo-
pyranosyl)-(1!6)-a-d-mannopyranoside (17): Sodium metal (87 mg) was
added in small portions at ꢀ788C under Ar to a solution of 16 (333 mg,
324 mmol) in THF (1 mL) and liquid ammonia (ca.5 mL). The mixture
was heated at refluxat room temperature for 10 min, while the blue
color of the solution persisted. The reaction was quenched by careful ad-
dition of ethanol. The mixture was carefully evaporated and chromato-
graphed on spherical silica gel (iPrOH/H2O/28% NH3 7:3:1) to give 17
(66 mg, 42%) as an amorphous solid: Rf = 0.23 (iPrOH/H2O/28% NH3
1
ide 20 (116 mg, 85%) as a syrup: [a]2D4 = +13.8 (c = 1.04 in CHCl3); H
7:3:1); m.p. 135–1378C; [a]D23
=
+40.1 (c = 0.96 in H2O); 1H NMR
NMR (400 MHz, CDCl3, 258C, TMS): d = 7.37–7.14 (m, 30H; Ph”6),
3
3
3
5.43 (t, J2,3 = 2.3 Hz, 1H; H2’’), 5.28 (d, J1,2 = 1.7 Hz, 1H; H1’’), 4.87–
(400 MHz, D2O, 40 8C, DOH): d = 5.27 (d, J1,2 = 1.8 Hz, 1H; H1’’),
3
3
3
3
4.42 (m, 12H; CH2Ph”6), 4.83 (d, J1,2 = 1.7 Hz, 1H; H1), 4.27 (d, J1,2
= 7.6 Hz, 1H; H1’), 4.13 (dd, J2,3 = 3.4 Hz, 1H; H2), 4.07–3.99 (m, 4H;
4.97 (d, J1,2 = 1.2 Hz, 1H; H1), 4.60 (d, J1,2 = 7.8 Hz, 1H; H1’), 4.36
3
3
2
3
(dd, J5,6a = 1.5, J6a,6b = 11.4 Hz, 1H; H6a), 4.31 (t, J2,3 = 2.9 Hz, 1H;
3
2
3
H4, H5’a, H3’’, H4’’), 3.93–3.65 (m, 7H; H3, H5, H6a, H6b, H5’’, H6a’’,
H2’’), 4.20 (dd, J4,5a = 5.2, J5a,5b = 11.7 Hz, 1H; H5a’), 4.15 (dd, J2,3
=
3
3
3
H6b’’), 3.56 (ddd, J3,4 = 9.6, J4,5a = 5.5, J4,5b = 10.8 Hz, 1H; H4’), 3.42
3.1 Hz, 1H; H2), 4.13–3.87 (m, 9H; H3, H4, H5, H6b, H3’’, H4’’, H5’’,
3
3
(dd, J2,3 = 9.6 Hz, 1H; H2’), 3.38 (s, 3H; OCH3), 3.35 (t, 1H; H3’), 3.14
H6a’’, H6b’’), 3.65–3.60 (m, 4H; H3’, OCH3), 3.54 (t, J4,5 = 11.0 Hz,
(t, J5a,5b = 11.6 Hz, 1H; H5b’), 2.16 (s, 3H; COCH3) ppm; 13C NMR
2
3
3
1H; H5b’), 3.22 (ddd, J3,4 = 9.3 Hz, 1H; H4’), 3.03 (dd, J2,3 = 9.2 Hz,
1H; H2) ppm; 13C NMR (100.6 MHz, D2O, 40 8C, acetone): d = 105.0
(C1’), 102.3 (C1’’), 101.6 (C1), 87.4 (C3’), 74.5, 72.0, 71.15, 71.1, 71.0, 67.6,
67.2 (C3, C4, C5, C2’’, C3’’, C4’’, C5’’), 70.5 (C2), 69.8 (C6), 66.2 (C5’),
61.6 (C6’’), 56.1 (C2’), 55.5 (OCH3), 51.6 (C4’) ppm; HRMS (ESI): calcd
for C18H35N2O13 [M+H]+: 487.2139; found 487.2136; elemental analysis
calcd (%) for C18H34N2O13·H2O (504.5): C 42.85, H 7.19, N 5.55; found: C
43.03, H 6.93, N 5.73.
(100.6 MHz, CDCl3, 258C): d
= 170.5 (C=O), 138.45, 138.4, 138.35,
138.3, 138.0, 137.9, 128.35, 128.3, 128.25, 128.2, 128.0, 127.9, 127.7, 127.65,
127.6, 127.55, 127.5, 127.4 (Ph”6), 101.8 (C1’), 98.9 (C1’’), 98.0 (C1), 79.4
(C3’), 78.2 (C3), 77.9, 74.9, 74.0, 72.4, 71.7 (C4, C5, C3’’, C4’’, C5’’), 75.1,
75.0, 73.5, 73.1, 71.9, 71.5 (CH2Ph”6), 74.3 (C2), 69.6, 68.4 (C6, C6’’),
69.0 (C2’’), 64.9 (C2’), 63.8 (C5’), 61.2 (C4’), 54.8 (OCH3), 21.1
(CH3CO) ppm; HRMS (ESI): calcd for C62H68N6O14Na [M+Na]+:
1143.4691; found 1143.4690.
Methyl (2,4-diamino-2,4-dideoxy-b-d-xylopyranosyl)-(1!2)-a-d-manno-
pyranoside (19): H2S gas was bubbled for 10 min at 08C into a solution
of methyl (2,4-diazido-2,4-dideoxy-b-d-xylopyranosyl)-(1!2)-a-d-manno-
pyranoside (18; 68 mg, 104 mmol) in pyridine/H2O (1:1, 4 mL). The mix-
ture was kept at room temperature for 12 h, evaporated, and chromato-
graphed on silica gel (CHCl3/MeOH/H2O 3:1:0, then 65:35:6) to give a
product with an Rf value of 0.29 (CHCl3/MeOH/H2O 65:35:6). The prod-
uct was dissolved in liquid ammonia (ca. 5 mL), and sodium was added
to the solution in small portions at ꢀ788C until the blue color of the so-
lution was maintained for more than 10 min. After addition of ethanol,
the solution was carefully evaporated and chromatographed on spherical
silica gel (iPrOH/H2O/28% NH3 8:1:1 then 7:3:1) to give 19 (13 mg,
Methyl (3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-diazido-2,4-
dideoxy-b-d-xylopyranosyl)-(1!2)-3,4,6-tri-O-benzyl-a-d-mannopyrano-
side (21): A solution of NaOMe in MeOH (50 mm, 2 mL) was added to a
stirred solution of 20 (116 mg, 103 mmol) in CH2Cl2 (0.4 mL). After 15 h,
the reaction mixture was evaporated and chromatographed on a column
of silica gel (hexane/ethyl acetate 2:1) to give 21 (86 mg, 78%) as a
syrup: Rf = 0.18 (hexane/ethyl acetate 2:1); [a]2D2 = +73.6 (c = 1.83 in
CHCl3); 1H NMR (400 MHz, CDCl3, 258C, TMS): d = 7.38–7.14 (m,
3
3
30H; Ph”6), 5.29 (d, J1,2 = 1.4 Hz, 1H; H1’’), 4.83 (d, J1,2 = 1.8 Hz,
3
1H; H1), 4.87–4.42 (m, 12H; CH2Ph”6), 4.27 (d, J1,2 = 7.6 Hz, 1H;
H1’), 4.13–4.12 (bm, 2H; H2, H2’), 4.06–4.01 (m, 2H; H5a’, H5’’), 3.98 (t,
3
3J3,4
=
2
3J4,5 = 9.6 Hz, 1H; H4’’), 3.91 (m, 2H; H3, H3’’), 3.84 (dd, J5,6a
=
40%) as a white solid: Rf = 0.19 (iPrOH/H2O/28% NH3 8:1:1); [a]D24
=
ꢀ13.2 (c = 0.57 in H2O); 1H NMR (400 MHz, D2O, 70 8C, DOH): d =
3.5, J6a,6b 10.8 Hz, 1H; H6a’’), 3.78 (dt, 1H; H5), 3.73–3.65 (m, 4H; H4,
H6a, H6b, H6b’’), 3.54 (ddd, J4,5a = 5.5, J4,5b = 10.7 Hz, 1H; H4’),
3
3
3
3
5.33 (d, J1,2 = 1.8 Hz, 1H; H1), 5.14 (d, J1,2 = 8.2 Hz, 1H; H1’), 4.68
2
3
2
3
3.44–3.35 (m, 5H; H2’, H3’, OCH3), 3.13 (t, J5a,5b = 11.6 Hz, 1H; H5b’),
(dd, J4,5a = 5.2 Hz, J5a,5b = 11.9 Hz, 1H; H5a’), 4.59 (dd, J2,3 = 3.5 Hz,
2.53 (brs, 1H; OH) ppm; 13C NMR (100.6 MHz, CDCl3, 258C): d
=
3
2
1H; H2), 4.34 (dd, J5,6a = 2.6, J6a,6b = 12.5 Hz, 1H; H6a), 4.30 (dd,
3J3,4 = 9.5 Hz, 1H; H3), 4.27 (dd, J5,6b = 4.8 Hz, 1H; H6b), 4.20 (dd,
3
138.4, 138.3, 138.0, 137.9, 128.5, 128.3, 128.25, 128.2, 127.9, 127.85, 127.7,
127.6, 127.55, 127.45, 127.4 (Ph”6), 101.9 (C1’), 100.6 (C1’’), 98.0 (C1),
79.9 (C3’’), 79.1 (C3’), 78.3 (C3), 75.1, 75.0, 73.5, 73.1, 72.1, 71.5 (CH2Ph”
6), 74.9 (C4), 74.3 (C2), 73.9 (C4’’), 72.0 (C5’’), 71.7 (C5), 69.6 (C6), 68.7
3J2,3 = 10.1, J3,4 = 9.9 Hz, 1H; H3’), 4.15 (dd, J4,5 = 9.9 Hz, 1H; H4),
3
3
3
4.08 (ddd, 1H; H5), 4.00 (dd, J4,5b = 10.7 Hz, 1H; H5b’), 3.89 (s, 3H;
OCH3), 3.77 (ddd, 1H; H4’), 3.54 (dd, 1H; H2’) ppm; 13C NMR
6486
www.chemeurj.org
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2005, 11, 6478 – 6490

Improvement of the Bending Ability of a Hinged Trisaccharide
FULL PAPER
3
(C2’’), 68.5 (C6’’), 64.9 (C2’), 63.8 (C5’), 61.4 (C4’), 54.8 (OCH3) ppm;
HRMS (ESI): calcd for C60H66N6O13Na [M+Na]+: 1101.4586; found
1101.4587; elemental analysis calcd (%) for C60H66N6O13 (1079.2): C
66.78, H 6.16, N 7.79; found: C 66.60, H 6.15, N 7.58.
(dd, J2,3 = 3.2 Hz, 1H; H2’’), 4.52–4.44 (m, 5H; H3, H6a, H3’, H3’’,
3
H6b’’), 4.41–4.35 (m, 3H; H6b, H5’’, H6b’’), 4.30, 4.27 (t”2, J3,4
=
3J4,5
3
= 9.5, J3,4
=
3J4,5 = 9.9 Hz, 2H; H4, H4’’), 4.24–4.20 (m, 1H; H5), 4.13
3
3
(dd, J4,5b = 4.8 Hz, 1H; H5b’), 3.90 (dt, J3,4 = 4.8 Hz, 1H; H4’), 3.86
3
(dd, J2,3 = 3.8 Hz, 1H; H2’), 2.53 ppm (s, 9H; ZnOCOCH3).
Methyl (3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-
dideoxy-b-d-xylopyranosyl)-(1!2)-2,3,6-tri-O-benzyl-a-d-mannopyrano-
side (22): Ar gas was bubbled at 08C for 20 min into a solution of 21
(629 mg, 583 mmol) in pyridine/H2O (10:1, 28 mL), followed by H2S gas
for 10 min. The mixture was kept at room temperature for 15 h. After
the mixture had been evaporated, the residue was taken up with metha-
nol, and the insoluble material was removed by celite filtration. The fil-
trate was evaporated and chromatographed on spherical silica gel
(CHCl3/MeOH 15:1) to give 22 (485 mg, 81%) as an amorphous solid:
Methyl (2,4-diazido-2,4-dideoxy-a,b-d-xylopyranosyl)-(1!6)-2,3,4-tri-O-
benzyl-a-d-galactopyranoside (27):
A mixture of methyl 2,3,4-tri-O-
benzyl-a-d-galactopyranoside (25; 1.621 g, 3.49 mmol) and crushed MS
(4 Š; 3 g) in CH3CN (20 mL) was stirred under Ar for 1 h and cooled at
ꢀ408C. TMSOTf (85 mL, 470 mmol), and then a solution of 2,4-diazido-
2,4-dideoxy-a,b-d-xylopyranosyl trichloroacetimidate (24;[7] 900 mg,
2.33 mmol, a:b 1:1) in CH3CN (10 mL), were slowly added to the mix-
ture. The temperature was allowed to increase slowly to room tempera-
ture over 3 h. The reaction was quenched by addition of triethylamine
(130 mL, 930 mmol). The insoluble material was removed by celite filtra-
tion, and the filtrate was evaporated and chromatographed on a column
of silica gel (hexane/ethyl acetate 10:1 to 1:1) to give disaccharide 26
=
Rf = 0.20 (CHCl3/MeOH 15:1); [a]2D4 +23.5 (c = 1.14 in MeOH); 1H
NMR (400 MHz, CDCl3, 258C, TMS): d = 7.39–7.17 (m, 30H; Ph”6),
3
5.11 (d, J1,2 = 2.7 Hz, 1H; H1’’), 4.91–4.42 (m, 12H; CH2Ph”6), 4.84 (d,
3
3J1,2 = 1.5 Hz, 1H; H1), 4.20 (d, J1,2 = 7.8 Hz, 1H; H1’), 4.07 (brs, 1H;
3
H2), 3.99–3.96 (m, 2H; H2’’, H5’’), 3.78 (t, J3,4
=
3J4,5 = 8.7 Hz, 1H;
(1.380 g) as a syrup; Rf
= 0.27 (hexane/EtOAc 9:2). A solution of
3
2
NaOMe in MeOH (1m, 0.4 mL) was added to a stirred solution of 26
(1.380 g) in methanol (20 mL). After 18 h, the reaction mixture was
evaporated and chromatographed on a column of silica gel (hexane/ethyl
acetate 4:1 to 3:1) to give 27 (834 mg, 55%, a/b 1:2) as a syrup: Rf
0.20 (hexane/ethyl acetate 3:1); H NMR (400 MHz, CDCl3, 258C, TMS):
d = 7.41–7.25 (m, 15H; Ph-ab”3), 5.00–4.58 (m, 15H; H-1ab, CH2Ph-
ab”3), 4.64 (d, J1,2 = 3.5 Hz, 0.33H; H1’a), 4.22 (d, J1,2 = 7.8 Hz,
0.67H; H1’b), 4.06–4.01 (m, 1H; H2ab), 3.96–3.85, 3.78–3.63, 3.59–3.42,
3.36–3.28 (each m, 8.33H; H3a, H4a, H5a, H6aa, H6ba, H3’a, H4’a,
H5a’a, H5b’a, H3b, H4b, H5b, H6ab, H6bb, H3’b, H4’b, H5a’b), 3.39 (s,
H4’’), 3.74–3.66 (m, 3H; H4, H6a, H6b), 3.64 (dd, J5,6a = 5.3, J6a,6b
=
3
10.4 Hz, 1H; H6a’’), 3.58 (dd, J5,6b = 2.3 Hz, 1H; 6b’’), 3.34 (s, 3H;
3
3
OCH3), 3.18 (t, J2,3
=
3J3,4 = 9.3 Hz, 1H; H3’), 3.08 (dd, J4,5b = 10.0,
2J5a,5b = 11.1 Hz, 1H; H5b’), 2.93 (dt, J4,5a = 5.0 Hz, 1H; H4’), 2.85 (dd,
1H; H2’), 2.08 (brs, 5H; NH2, OH) ppm; 13C NMR (100.6 MHz, CDCl3,
258C): d = 138.6, 138.3, 138.17, 138.1, 138.0, 137.95, 128.4, 128.3, 128.25,
128.2, 127.9, 127.85, 127.8, 127.75, 127.6, 127.5, 127.45, 127.4, 127.35 (Ph”
6), 104.1 (C1’), 101.1 (C1’’), 98.7 (C1), 87.8 (C3’), 79.0 (C3’’), 78.2 (C3),
75.0, 74.3, 73.3, 73.1, 72.3, 71.3 (CH2Ph”6), 74.4, 72.2, 71.4, 69.3 (C4, C5,
C4’, C2’’, C5’’), 74.0 (C2), 69.1 (C6), 69.1 (C6’’), 67.6 (C5’), 55.3 (C2’),
54.8 (OCH3), 51.9 (C4’) ppm; HRMS (ESI): calcd for C60H71N2O13
[M+H]+: 1027.4956; found 1027.4955; elemental analysis calcd (%) for
3
=
1
3
3
3
2.01H; OCH3b), 3.37 (s, 0.99H; OCH3a), 3.21 (dd, J2,3 = 9.6 Hz, 0.67H;
3
3
H2’b), 3.13 (dd, J2,3 = 10.1 Hz, 0.33H; H2’a), 3.06 (dd, J4,5b = 10.8,
2J5a,5b = 11.1 Hz, 0.67H; H5b’b), 2.74 (d, J3,OH = 3.2 Hz, 0.67H; OHb),
3
C60H70N2O13·1= H2O (1036.2): C 69.55, H 6.91, N 2.70; found: C 69.61, H
2
3
2.65 (d, J3,OH
CDCl3, 258C): d
=
3.7 Hz, 0.33H; OHa) ppm; 13C NMR (100.6 MHz,
6.95, N 2.81.
= 138.75, 138.7, 138.5, 138.4, 138.35, 128.4, 128.35,
Methyl (a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-dideoxy-b-d-xylo-
pyranosyl)-(1!2)-a-d-mannopyranoside (23): Sodium metal (68 mg) was
added in small portions at ꢀ788C under Ar to a solution of 22 (92 mg,
90 mmol) in THF (0.5 mL) and liquid ammonia (4 mL). The mixture was
heated at refluxat room temperature for 40 min, while the blue color of
the solution persisted. The reaction was quenched by careful addition of
ethanol. The mixture was carefully evaporated and chromatographed on
spherical silica gel (iPrOH/H2O/28% NH3 7:3:1) to give 23 (34 mg, 77%)
as an amorphous solid: Rf = 0.30 (iPrOH/H2O/28% NH3 7:3:1); m.p.
128.32, 128.30, 128.2, 128.1, 127.7, 127.65, 127.6, 127.55, 127.5, 127.45
(Phab”3), 102.6 (C1’b), 98.8 (C1b), 98.7 (C1a), 97.4 (C1’a), 79.0, 78.9,
76.3, 75.4, 75.1, 70.8, 69.7, 62.0, 60.8 (C2a, C3a, C4a, C5a, C3’a, C4’a,
C2b, C3b, C4b, C5b, C4’b), 74.6, 74.5, 73.55, 73.5, 73.5, 73.4 (CH2Phab”
3), 74.0 (C3’b), 69.0 (C6b), 67.4, 59.6 (C6a, 5’a), 66.4 (C2’b), 63.8 (C5’b),
63.2 (C2’a), 55.4 (OCH3b), 55.3 (OCH3a) ppm; HRMS (ESI): calcd for
C33H38N6O8Na [M+Na]+: 669.2649; found 669.2679; elemental analysis
calcd (%) for C33H38N6O8·1= H2O (650.3): C 60.95, H 5.95, N 12.92;
5
found: C 60.93, H 5.89, N 12.74.
1
165–1678C; [a]2D3 = +10.9 (c = 1.16 in H2O); H NMR (400 MHz, D2O,
Methyl (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-
diazido-2,4-dideoxy-a,b-d-xylopyranosyl)-(1!6)-2,3,4-tri-O-benzyl-a-d-
galactopyranoside (28): A mixture of 27 (396 mg, 612 mmol) and crushed
MS (4 Š, ca. 1 g) in CH2Cl2 (8 mL) was stirred under Ar for 1 h and
cooled at ꢀ408C. TMSOTf (22 mL, 122 mmol) in CH2Cl2 (220 mL), and
then a solution of 11 (586 mg, 921 mmol) in CH2Cl2 (8 mL), were slowly
added to the mixture. The temperature was allowed to increase slowly to
room temperature over 3 h. The reaction was quenched by addition of
triethylamine (34 mL, 244 mmol). The insoluble material was removed by
celite filtration, and the filtrate was evaporated and chromatographed on
a column of silica gel (toluene/ethyl acetate 15:1 to 8:1) to give trisac-
charide 28 (402 mg, 59%) as a foam (the corresponding a isomer was ob-
3
3
258C, DOH): d = 5.10 (d, J1,2 = 2.1 Hz, 1H; H1’’), 4.93 (d, J1,2
=
3
3
1.7 Hz, 1H; H1), 4.44 (d, J1,2
=
7.9 Hz, 1H; H1’), 4.15 (dd, J2,3
=
3
3
3.4 Hz, 1H; H2’’), 4.12 (dd, J2,3 = 3.5 Hz, 1H; H2), 4.05 (dd, J4,5a = 5.3,
2J5a,5b = 11.9 Hz, 1H; H5a’), 3.97–3.66 (m, 10H; H3, H4, H5, H6a, H6b,
3
H3’’, H4’’, H5’’, H6a’’, H6b’’), 3.48 (s, 3H; OCH3), 3.44 (t, J2,3
= =
3J3,4
3
9.3 Hz, 1H; H3’), 3.34 (t, J4,5 = 11.1 Hz, 1H; H5b’), 3.08 (ddd, 1H;
H4’), 2.90 (dd, 1H; H2’) ppm; 13C NMR (100.6 MHz, D2O, 25 8C, ace-
tone): d = 102.4 (C1’), 102.0 (C1’’), 98.7 (C1), 87.1 (C3’), 76.7 (C2), 74.0,
72.7, 70.4, 69.6, 67.2, 67.0 (C3, C4, C5, C3’’, C4’’, C5’’), 70.6 (C2’’), 65.7
(C5’), 61.1, 60.9 (C6, C6’’), 55.2 (C2’), 55.0 (OCH3), 50.9 (C4’) ppm;
HRMS (ESI): calcd for C18H35N2O13 [M+H]+: 487.2139; found 487.2137;
elemental analysis calcd (%) for C18H34N2O13·3= H2O (513.5): C 42.10, H
2
tained as a mixture with trichloroacetamide and was not isolable): Rf
=
7.26, N 5.46; found: C 42.00, H 6.94, N 5.58.
1
0.20 (toluene/ethyl acetate 10:1); [a]2D3 = +26.1 (c = 0.99 in CHCl3); H
Compound 23 (16 mm)
+
0.5 equiv Hg(OAc)2: 1H NMR (400 MHz,
NMR (400 MHz, CDCl3, 258C, TMS): d = 7.40–7.14 (m, 30H; Ph”6),
3
50 mm [D3]AcONa buffer, 708C, DOH): d = 5.53 (d, J1,2 = 1.8 Hz, 1H;
3
3
5.42 (t, J2,3 = 2.7 Hz, 1H; H2’’), 5.25 (d, J1,2 = 1.7 Hz, 1H; H1’’), 4.97–
3
3
3
H1’’), 5.38 (d, J1,2 = 1.7 Hz, 1H; H1), 5.23 (d, J1,2 = 3.4 Hz, 1H; H-1’),
4.48 (m, 13H; H1’, CH2Ph”6), 4.21 (d, J1,2 = 7.9 Hz, 1H; H1), 4.04–3.83
2
3
4.92 (brd, J5a,5b = 12.7 Hz, 1H; H-5a’), 4.54 (dd, J2,3 = 3.4 Hz, 1H;
(m, 9H; H2, H3, H4, H5, H5a’, H3’’, H4’’, H5’’, H6a’’), 3.77–3.67 (m,
3
3
3
H2), 4.51 (dd, J2,3 = 3.1 Hz, 1H; H2’’), 4.45–4.35 (m, 4H; H3, H6a, H3’’,
3H; H6a, H6b, H6b’’), 3.48 (ddd, J4,5a = 5.0, J4,5b = 11.0 Hz, 1H; H4’),
3
H6a’’), 4.32–4.24 (m, 3H; H6b, H5’’, H6b’’), 4.22–4.10 (m, 3H; H4, H3’,
3.37 (s, 3H; OCH3), 3.31 (t, J2,3 = 9.6 Hz, 1H; H3’), 3.16 (dd, 1H; H2’),
3
2
3.08 (t, J5a,5b
=
11.8 Hz, 1H; H5b’), 2.15 (s, 3H; COCH3) ppm; 13C
H4’’), 4.15–4.10 (m, 1H; H5), 4.02 (dd, J4,5b = 5.3 Hz, 1H; H5b’), 3.95
(s, 3H; OCH3), 3.89 (brdt, 1H; H4’), 3.82 (brt, 1H; H2’), 2.42 ppm (s,
3H; HgOCOCH3).
NMR (100.6 MHz, CDCl3, 258C): d = 170.4 (C=O), 138.7, 138.4, 138.3,
138.2, 137.9, 128.35, 128.33, 128.3, 128.25, 128.2, 128.0, 127.95, 127.9,
127.7, 127.65, 127.6, 127.55, 127.5, 127.45 (Ph”6), 102.9 (C1’), 98.85, 98.8
(C1, C1’’), 79.3 (C3’), 78.9, 77.8, 76.2, 75.3, 74.0, 72.4, 69.6 (C2, C3, C4,
C5, C3’’, C4’’, C5’’), 75.1, 74.6, 73.5, 73.4, 73.3, 71.8 (CH2Ph”6), 69.1
(C6), 68.9 (C2’’), 68.5 (C6’’), 65.2 (C2’), 63.5 (C5’), 61.4 (C4’), 55.4
Compound 23 (16 mm)
50 mm [D3]AcONa buffer, 808C, DOH): d = 5.62 (s, J1,2 = 2.3 Hz, 1H;
+
1.5 equiv Zn(OAc)2: 1H NMR (400 MHz,
3
3
3
H1’’), 5.46 (s, 1H; H1), 5.37 (d, J1,2 = 2.8 Hz, 1H; H1’), 5.04 (d, J4,5a
=
2
3
2.8, J5a,5b = 12.1 Hz, 1H; H5a’), 4.63 (d, J2,3 = 3.8 Hz, 1H; H2), 4.60
Chem. Eur. J. 2005, 11, 6478 – 6490
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
6487

H. Yuasa et al.
3
(OCH3), 21.1 (CH3CO) ppm; HRMS (ESI): calcd for C62H68N6O14Na
[M+Na]+: 1143.4691; found 1143.4701; elemental analysis calcd (%) for
(400 MHz, D2O, 40 8C, DHO): d = 5.15 (d, J1,2 = 2.0 Hz, 1H; H1’’),
3
3
4.95 (d, J1,2 = 2.9 Hz, 1H; H1), 4.45 (d, J1,2 = 8.0 Hz, 1H; H1’), 4.20
3
3
C62H68N6O14·1= H2O (1130.3): C 65.89, H 6.15, N 7.44; found: C 65.83, H
(dd, J2,3 = 3.3 Hz, 1H; H2’’), 4.17 (m, 1H; H5), 4.12 (dd, J5,6a = 3.8,
2
3
6.04, N 7.39.
2J6a,6b = 11.0 Hz, 1H; H6a), 4.08 (m, 1H; H4), 4.07 (dd, J4,5a = 5.2,
2J5a,5b = 11.6 Hz, 1H; H5a’), 4.00 (dd, J5,6a = 2.1, J6a,6b = 12.1 Hz, 1H;
3
2
Methyl (3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-diazido-2,4-
dideoxy-b-d-xylopyranosyl)-(1!6)-2,3,4-tri-O-benzyl-a-d-galactopyrano-
side (29): A solution of NaOMe in MeOH (0.1m, 0.1 mL) was added to a
stirred solution of 28 (77 mg, 69 mmol) in CH2Cl2 (1 mL) and methanol
(1 mL). After 18 h, the reaction mixture was evaporated and chromato-
graphed on a column of silica gel (toluene/ethyl acetate 8:1 to 4:1) to
give 29 (64 mg, 87%) as a foam: Rf = 0.20 (toluene/ethyl acetate 4:1);
[a]2D3 = +30.7 (c = 0.94 in CHCl3); 1H NMR (400 MHz, CDCl3, 258C,
3
3
H6a’’), 3.96 (dd, J3,4 = 9.5 Hz, 1H; H3’’), 3.94 (dd, J5,6b = 8.2 Hz, 1H;
H6b), 3.93–3.89 (m, 3H; H2, H3, H5’’), 3.84 (dd, J5,6b = 6.5 Hz, 1H;
3
3
H6b’’), 3.77 (dd, J4,5 = 9.5 Hz, 1H; H4’’), 3.53 (s, 3H; OCH3), 3.46 (t,
3J2,3
=
3J3,4 = 9.3 Hz, 1H; H3’), 3.40 (dd, J4,5b = 10.8 Hz, 1H; H5b’),
3
3.06 (ddd, 1H; H4’), 2.85 (dd, 1H; H2’) ppm; 13C NMR (67.8 MHz, D2O,
408C, acetone): d 107.2 (C1’), 104.4 (C1’’), 102.1 (C1), 90.1 (C3’),
=
76.40 (C5’’), 73.1 (C2’’), 72.9 (C3’’), 72.4 (C6), 72.1 (C5), 71.9 (C4), 71.85,
70.7 (C2, C3), 69.5 (C4’’), 68.4 (C5’), 63.6 (C6’’), 58.2 (C2’), 57.9 (OCH3),
53.6 (C4’) ppm; HRMS (ESI): calcd for C18H35N2O13 [M+H]+: 487.2139;
found 487.2138.
3
TMS): d = 7.40–7.16 (m, 30H; Ph”6), 5.27 (d, J1,2 = 1.5 Hz, 1H; H1’’),
3
4.97–4.49 (m, 13H; H1’, CH2Ph”6), 4.22 (d, J1,2 = 7.9 Hz, 1H; H1’),
3
4.12 (dd, J2,3 = 3.1 Hz, 1H; H2’’), 4.04–4.01 (m, 2H; H2, H5’’), 3.97–3.86
3
2
(m, 6H; H3, H4, H5, H5a’, H3’’, H4’’), 3.81 (dd, J5,6a = 3.7, J6a,6b
=
Methyl (2,4-diamino-2,4-N-carbonyl-2,4-dideoxy-b-d-xylopyranosyl)-(1!
2)-a-d-mannopyranoside (34): A solution of 1,1’-carbonylbis-1H-imida-
zole (12 mg, 86 mmol) in DMF (1.5 mL) was added at room temperature
to a stirred solution of 19 (23 mg, 71 mmol) in DMF (3 mL). After 14 h at
room temperature the reaction was incomplete, so the bath temperature
was raised to 1208C and the reaction was continued for further 24 h. The
mixture was evaporated and the residue was taken up with H2O and
passed through a column of Dowex50W X-8 (H
were chromatographed on a column of spherical silica gel (CHCl3/MeOH
5:1 to CHCl3/MeOH/H2O 65:35:6) to give 34 (12 mg, 48%) as an amor-
phous solid: Rf = 0.20 (CHCl3/MeOH/H2O 65:35:6); [a]2D6 = ꢀ67.3 (c =
0.43 in H2O); 1H NMR (400 MHz, D2O, 25 8C, DHO): d = 4.98 (s, 1H;
10.8 Hz, 1H; H6a’’), 3.77–3.68 (m, 3H; H6a, H6b, H6b’’), 3.47 (ddd, 3J3,4
= 9.5, J4,5a = 5.3, J4,5b = 10.8 Hz, 1H; H4’), 3.37 (s, 3H; OCH3), 3.34
3
3
3
2
(t, J2,3 = 9.8 Hz, 1H; H3’), 3.16 (dd, 1H; H2’), 3.08 (t, J5a,5b = 11.6 Hz,
1H; H5b’) ppm; 13C NMR (100.6 MHz, CDCl3, 258C): d = 138.7, 138.4,
138.3, 138.2, 137.9, 128.5, 128.4, 128.35, 128.3, 128.25, 128.2, 128.0, 127.9,
127.85, 127.8, 127.75, 127.7, 127.6, 127.55, 127.5, 127.45 (Ph”6), 103.0
(C1’), 100.6 (C1’’), 98.8 (C1), 79.8, 78.9, 75.3, 73.9, 69.6 (C3, C4, C5, C3’’,
C4’’), 79.0 (C3’), 76.2 (C2), 75.1, 74.6, 73.5, 73.4, 73.3, 72.0 (CH2Ph”6),
72.0 (C5’’), 69.1 (C6), 68.6 (C2’’, C6’’), 65.1 (C2’), 63.5 (C5’), 61.6 (C4’),
55.4 (OCH3) ppm; HRMS (ESI): calcd for C60H66N6O13Na [M+Na]+:
1101.4586; found 1101.4583; elemental analysis calcd (%) for
C60H66N6O13 (1079.2): C 66.78, H 6.16, N 7.79; found: C 66.81, H 6.29, N
7.73.
+
form). The effluents
3
2
H1), 4.88 (d, J1,2 = 1.5 Hz, 1H; H1’), 4.36 (d, J5a,5b = 11.9 Hz, 1H;
3
3
H5’), 4.23 (t, J2,3
1H; H2), 3.91–3.85 (m, J3,4 = 6.1, J6a,6b = 12.2 Hz, 2H; H3, H6a), 3.76
=
3J3,4 = 3.8 Hz, 1H; H3’), 4.05 (dd, J2,3 = 3.8 Hz,
3
2
Methyl (3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-
dideoxy-b-d-xylopyranosyl)-(1!6)-2,3,4-tri-O-benzyl-a-d-galactopyrano-
side (30): Ar gas was bubbled at 08C for 20 min into a solution of 29
(364 mg, 338 mmol) in pyridine/H2O (10:1, 14 mL), followed by H2S gas
for 20 min. The mixture was kept at room temperature for 12 h. After
the mixture had been evaporated, the residue was taken up with metha-
nol, and the insoluble material was removed by celite filtration. The fil-
trate was evaporated and chromatographed on silica gel (CHCl3/MeOH
15:1) to give 30 (298 mg, 86%) as a foam: Rf = 0.20 (CHCl3/MeOH
15:1); [a]2D5 = +46.5 (c = 1.03 in MeOH); 1H NMR (400 MHz, CDCl3,
3
3
(ddd, J5,6b = 4.3 Hz, 1H; H6b), 3.64–3.62 (m, J5,6a = 1.7 Hz, 2H; H4,
H5), 3.57–3.52 (m, J3,4 = 1.7 Hz, 2H; H2’, H5b’), 3.43 (m, 1H; H4’),
3
3.40 (s, 3H; OCH3) ppm; 13C NMR (100.6 MHz, D2O, 30 8C, acetone):
d = 159.6 (C=O), 98.6 (C1’), 97.9 (C1), 74.4 (C2), 73.1 (C5), 70.1 (C3),
67.6 (C4), 63.4 (C3’), 61.3 (C6), 60.8 (C5’), 55.5 (OCH3), 49.1 (C2’), 48.8
(C4’) ppm; HRMS (ESI): calcd for C13H23N2O9 [M+H]+: 351.1404; found
351.1408.
Methyl (b-d-galactopyranosyl)-(1!3)-(2,4-diamino-2,4-N-carbonyl-2,4-di-
deoxy-b-d-xylopyranosyl)-(1!6)-a-d-mannopyranoside (35): 1,1’-Car-
bonylbis-1H-imidazole (6 mg, 38 mmol) was added at room temperature
to a stirred solution of 6 (15 mg, 30.4 mmol) in DMF (2 mL). After 5 h,
the reaction mixture was evaporated and the residue was taken up with
3
258C, TMS): d = 7.39–7.17 (m, 30H; Ph”6), 5.08 (d, J1,2 = 2.9 Hz, 1H;
3
H1’’), 4.95–4.45 (m, 12H; CH2Ph”6), 4.66 (d, J1,2 = 3.5 Hz, 1H; H1),
3
3
4.07 (d, J1,2 = 7.5 Hz, 1H; H1’), 4.02 (dd, J2,3 = 10.1 Hz, 1H; H2),
3
3
+
4.06–4.00 (m, 1H; H5’’), 3.97 (dd, J2,3 = 3.2 Hz, 1H; H2’’), 3.92 (dd, J3,4
= 2.7 Hz, 1H; H3), 3.89–3.85 (m, 3H; H4, H5, H3’’), 3.83–3.78 (m, 2H;
H6a, H5a’), 3.82 (dd, J3,4 = 9.1, J4,5 = 7.5 Hz, 1H; H4’’), 3.69–3.51 (m,
3H; H6b, H6a’’, H6b’’), 3.34 (s, 3H; OCH3), 3.11 (t, J2,3
9.3 Hz, 1H; H3’), 3.02 (dd, J4,5b = 11.1, J5a,5b = 11.3 Hz, 1H; H5b’),
H2O and passed through a column of Dowex50W X-8 (H form). The
effluents were chromatographed on a column of spherical silica gel (ethyl
acetate/MeOH/H2O 5:3:1) to give 35 (14 mg, 87%) as an amorphous
solid: Rf = 0.27 (ethyl acetate/MeOH/H2O 5:3:1); m.p. 196–1988C; [a]D26
3
3
3
=
3J3,4
=
3
2
1
= ꢀ38.7 (c = 0.87 in H2O); H NMR (400 MHz, D2O, 30 8C, DHO): d =
3
3
3
3
2.85 (ddd, J4,5a
=
5.0 Hz, 1H; H4’), 2.64 (dd, J1,2
=
7.7 Hz, 1H;
4.99 (brs, 1H; H1’), 4.90 (d, J1,2 = 1.7 Hz, 1H; H1), 4.70 (d, J1,2 =
H2’) ppm; 13C NMR (67.8 MHz, CDCl3, 258C): d = 138.8, 138.6, 138.5,
138.0, 137.95, 137.9, 128.5, 128.4, 128.3, 128.25, 128.2, 128.15, 128.0,
127.95, 127.9, 127.85, 127.75, 127.7, 127.6, 127.55, 127.5, 127.4 (Ph”6),
105.3 (C1’), 101.1 (C1’’), 98.7 (C1), 88.2 (C3’), 79.0 (C3, C3’’), 76.4 (C2),
75.3 (C4), 74.6 (CH2Ph), 74.6 (C4’’), 74.3, 73.5, 73.3, 73.3, 72.4 (CH2Ph”
5), 72.2 (C5’’), 69.5 (C5), 69.5 (C2’’), 69.3 (C6’’), 68.9 (C6), 67.5 (C5’),
56.4 (C2’), 55.3 (OCH3), 52.2 (C4’) ppm; HRMS (ESI): calcd for
C60H71N2O13 [M+H]+: 1027.4956; found 1027.4958; elemental analysis
calcd (%) for C60H70N2O13·H2O (1045.2): C 68.95, H 6.94, N 2.68; found:
C 69.21, H 6.93, N 2.72.
7.6 Hz, 1H; H1’’), 4.50 (t, J2,3
=
3J3,4
=
3.7 Hz, 1H; H3’), 4.42 (d,
3
2J5a,5b = 11.8 Hz, 1H; H5a’), 4.18 (d, J6a,6b = 9.6 Hz, 1H; H6a), 4.05–
4.03 (m, 2H; H2, H4’’), 3.95–3.86 (m, 5H; H3, H4, H6b, H6a’’, H6b’’),
3.82–3.78 (m, 3H; H2’, H4’, H3’’), 3.75–3.70 (m, 3H; H5, H2’’, H5’’), 3.66
(brd, 1H; H5b’), 3.57 (s, 3H; OCH3) ppm; 13C NMR (100.6 MHz, D2O,
308C, acetone): d = 159.6 (C=O), 102.9 (C1’’), 102.1 (C1’), 101.5 (C1),
75.9, 72.8, 72.3, 71.4, 70.9, 70.4, 69.0, 67.6 (C2, C3, C4, C5, C2’’, C3’’, C4’’,
C5’’), 70.2 (C3’), 69.3 (C6), 61.4 (C6’’), 60.5 (C5’), 55.8 (OCH3), 47.9
(C4’), 47.5 (C2’) ppm; HRMS (ESI): calcd for C19H33N2O14 [M+H]+:
513.1932; found 513.1932; elemental analysis calcd (%) for
C19H32N2O14·2H2O (548.5): C 41.61, H 6.62, N 5.11; found: C 41.87, H
6.36, N 5.11.
2
Methyl (a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-dideoxy-b-d-xylo-
pyranosyl)-(1!6)-a-d-galactopyranoside (31): Sodium metal (95.8 mg)
was added in small portions at ꢀ788C under Ar to a solution of 30
(436 mg, 425 mmol) in THF (1 mL) and liquid ammonia (4 mL). The mix-
ture was heated at refluxat room temperature for 1 h, while the blue
color of the solution persisted. The reaction was quenched by careful ad-
dition of ethanol. The mixture was carefully evaporated and chromato-
graphed on spherical silica gel (iPrOH/H2O/28% NH3 7:3:1) to give 31
(101 mg, 49%) as an amorphous solid: Rf = 0.22 (iPrOH/H2O/28% NH3
Methyl (a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-N-carbonyl-2,4-di-
deoxy-b-d-xylopyranosyl)-(1!6)-a-d-mannopyranoside (36): A solution
of 1,1’-carbonylbis-1H-imidazole (6 mg, 36 mmol) in DMF (1 mL) was
added at room temperature to a stirred solution of 17 (17 mg, 35 mmol)
in DMF (2 mL). After 5 h, the reaction mixture was evaporated and the
residue was taken up with H2O and passed through a column of Dowex
50W X-8 (H+ form). The effluents were chromatographed on a column
of spherical silica gel (EtOAc/MeOH/H2O 5:3:1) to give 36 (15 mg,
7:3:1); m.p. 158–1598C; [a]D23
=
+72.3 (c = 0.22 in H2O); 1H NMR
6488
www.chemeurj.org
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2005, 11, 6478 – 6490

Improvement of the Bending Ability of a Hinged Trisaccharide
FULL PAPER
86%) as an amorphous solid: Rf
5:3:1); m.p. 178–1808C; [a]D25
ꢀ1.5 (c
(400 MHz, D2O, 30 8C, DOH): d = 5.09 (d, J1,2 = 1.5 Hz, 1H; H1’’),
=
0.25 (ethyl acetate/MeOH/H2O
where aobs, a12 h, and a0 h denote the optical rotations at the given time,
12 h, and 0 h, respectively.
=
=
0.66 in H2O); 1H NMR
3
Dichloro[methyl 2,4-diamino-2,4-dideoxy-b-d-xylopyranosyl-(1!2)-a-d-
mannopyranoside-N,N’]platinum (40): A solution of K2[PtCl4] (29 mg,
63 mmol) in [D3]AcONa/D2O buffer (50 mm, pH 7.0, 262 mL) was added
at 308C to a stirred solution of compound 19 (20 mg, 63 mmol) in the
same buffer (2157 mL). The reaction was monitored by optical rotation
(2.0 mL aliquot) at intervals of 0.5 h. After 12 h, the solution was passed
through the column of SephadexG-15 ( 1 = 2.5”100 cm) to give 40
(18 mg, 43%) as a pale yellow solid: m.p. 178–1798C; [a]2D5 = ꢀ44.3 (c =
1.00 in H2O); 1H NMR (400 MHz, D2O, 30 8C, DHO): d = 5.07 (s, 1H;
3
2
4.93 (brs, 1H; H1’), 4.88 (d, J1,2 = 1.7 Hz, 1H; H1), 4.39 (d, J5a,5b
=
3
11.9 Hz, 1H; H5a’), 4.36 (t, J2,3
=
3J3,4 = 3.5 Hz, 1H; H3’), 4.13 (dd,
2
3J2,3 = 3.2 Hz, 1H; H2’’), 4.12 (d, J6a,6b = 10.1 Hz, 1H; H6a), 4.07–4.04
(m, 2H; H2, H3’’), 4.01–3.76 (m, 8H; H3, H4, H5, H6b, H4’’, H5’’, H6a’’,
H6b’’), 3.70 (brs, 2H; H2’, H4’), 3.62 (brd, 1H; H5b’), 3.55 (s, 3H;
OCH3) ppm; 13C NMR (100.6 MHz, D2O, 30 8C, acetone): d = 159.4 (C=
O), 101.5 (C1’), 101.2 (C1), 99.3 (C1’’), 73.6, 72.1, 70.8, 70.6, 70.0, 67.3,
67.2, 67.0 (C2, C3, C4, C5, C3’, C3’’, C4’’, C5’’), 70.4 (C2’’), 68.7 (C6), 61.2
(C6’’), 60.0 (C5’), 55.2 (OCH3), 48.8 (C2’), 45.8 (C4’) ppm; HRMS (ESI):
calcd for C19H33N2O14 [M+H]+: 513.1932; found 513.1931.
3
2
H1’), 4.91 (d, J1,2 = 1.3 Hz, 1H; H1), 4.50 (d, J5a,5b = 13.1 Hz, 1H;
3
H5a’), 4.06 (dd, J2,3 = 3.5 Hz, 1H; H2), 3.89–3.86 (m, 2H; H3, H6a),
3
2
Methyl (a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-N-carbonyl-2,4-di-
deoxy-b-d-xylopyranosyl)-(1!2)-a-d-mannopyranoside (37): A solution
of 1,1’-carbonylbis-1H-imidazole (9 mg, 57 mmol) in DMF(1.5 mL) was
added at room temperature to a stirred solution of 23 (23 mg, 47 mmol)
in DMF (3 mL). After 5 h, the reaction mixture was evaporated and the
residue was taken up with H2O and passed through a column of Dowex
50W X-8 (H+ form). The effluents were chromatographed on a column
of spherical silica gel (ethyl acetate/MeOH/H2O 5:3:1) to give 37 (18 mg,
3.76 (dd, J5,6b = 5.5, J6a,6b = 12.4 Hz, 1H; H6b), 3.71–3.60 (m, 4H; H4,
H5, H3’, H5b’), 3.44 (s, 3H; OCH3), 2.78 (s, 1H; H2’), 2.68 (s, 1H;
H4’) ppm; 13C NMR (100.6 MHz, D2O, 30 8C, acetone): d = 98.2 (C1),
95.6 (C1’), 75.1 (C2), 73.3 (C5), 70.3 (C3), 67.3 (C4), 66.7 (C3’), 61.3
(C6), 56.8 (C5’), 55.6 (OCH3), 49.9 (C2’), 48.4 (C4’) ppm; HRMS (ESI):
calcd for C12H2435Cl2N2O8K195Pt [M+K]+: 628.0196; found 628.0195.
Dichloro[methyl b-d-galactopyranosyl-(1!3)-2,4-diamino-2,4-dideoxy-b-
d-xylopyranosyl-(1!6)-a-d-mannopyranoside-N,N’]platinum (41): A so-
lution of K2[PtCl4] (28 mg, 68 mmol) in [D3]AcONa/D2O buffer (50 mm,
pH 7.0, 283 mL) was added at 308C to a stirred solution of compound 6
(33 mg, 68 mmol) in the same buffer (2334 mL). The reaction was moni-
tored by optical rotation at intervals of 0.5 h. After 12 h, the solution was
passed through the column of SephadexG-15 ( 1 = 2.5”100 cm) to give
75%) as an amorphous solid: Rf
= 0.20 (EtOAc/MeOH/H2O 5:3:1);
[a]2D6 = ꢀ20.3 (c = 0.875 in H2O); 1H NMR (400 MHz, D2O, 25 8C,
3
DHO): d = 5.05 (d, J1,2 = 1.7 Hz, 1H; H1’’), 4.94 (brs, 1H; H1’), 4.93
3
2
(d, J1,2 = 1.5 Hz, 1H; H1), 4.43 (d, J5a,5b = 11.8 Hz, 1H; H5a’), 4.33 (t,
3J2,3 3J3,4 = 3.7 Hz, 1H; H3’), 4.08–4.06 (m, 2H; H2, H2’’), 4.01–3.66
=
(m, 9H; H3, H5, H6a, H6b, H4’, H3’’, H5’’, H6a’’, H6b’’), 3.74 (t, 2H;
H4, H4’’), 3.64–3.63 (m, 1H; H2’), 3.56 (brd, 1H; H5b’), 3.47 (s, 3H;
41 (24 mg, 46%) as a pale yellow solid: m.p. 2538C (decomp); [a]D30
=
ꢀ29.6 (c = 0.96 in H2O); 1H NMR (400 MHz, D2O, 30 8C, DHO): d =
OCH3) ppm; 13C NMR (67.8 MHz, D2O, 30 8C, acetone): d
= 159.7
3
3
5.09 (s, 1H; H1’), 4.89 (d, J1,2 = 1.5 Hz, 1H; H1), 4.62 (d, J1,2 = 7.8 Hz,
(C=O), 99.6 (C1’’), 99.2 (C1’), 98.6 (C1), 75.7 (C2), 73.9, 73.4 (C5, C5’’),
71.1 (C3’’), 70.6 (C2’’), 70.3 (C3’), 68.0, 67.4 (C4, C4’’), 67.4 (C3’), 61.6,
61.5 (C6, C6’’), 60.6 (C5’), 55.4 (OCH3), 49.2 (C2’), 45.9 (C4’) ppm;
HRMS (ESI): calcd for C19H33N2O14 [M+H]+: 513.1932; found 513.1928.
3
2
1H; H1’’), 4.48 (dd, J4,5a = 1.9, J5a,5b = 13.2 Hz, 1H; H5a’), 4.21 (d,
2J6a,6b = 9.9 Hz, 1H; H6a’’), 4.05 (dd, J2,3 = 3.2 Hz, 1H; H2), 4.02 (d,
3
3J3,4 = 3.5 Hz, 1H; H4’’), 3.94–3.75 (m, 10H; H3, H4, H5, H6a, H6b,
3
H3’, H5b’, H3’’, H5’’, H6b’’), 3.64 (dd, J2,3 = 9.9 Hz, 1H; H2’’), 3.54 (s,
Methyl (a-d-mannopyranosyl)-(1!3)-(2,4-diamino-2,4-N-carbonyl-2,4-di-
deoxy-b-d-xylopyranosyl)-(1!6)-a-d-galactopyranoside (38): 1,1’-Car-
bonylbis-1H-imidazole (6 mg, 38 mmol) in DMF (1 mL) was added at
room temperature to a stirred solution of 31 (15 mg, 31 mmol) in DMF
(2 mL). After 5 h, the reaction mixture was evaporated and the residue
was taken up with H2O and passed through a column of Dowex50W X-8
(H+ form). The effluents were chromatographed on a column of spheri-
cal silica gel (ethyl acetate/MeOH/H2O 5:3:1) to give 38 (11 mg, 68%) as
3H; OCH3), 3.04 (brs, 1H; H4’), 3.02 (brs, 1H; H2’) ppm; 13C NMR
(100.6 MHz, D2O, 30 8C, acetone): d
= 103.5 (C1’’), 101.6 (C1), 98.4
(C1’), 76.1, 74.1 (C3’), 72.9, 72.0, 71.3 (C2’’), 71.0, 70.5 (C2), 69.1 (C4’’),
68.6, 67.6, 61.7, 56.9 (C5’), 55.7 (OCH3), 47.9 (C2’), 47.5 (C4’) ppm;
HRMS (ESI): calcd for C18H3435Cl2N2O13K195Pt [M+K]+: 790.0723; found
790.0688; elemental analysis calcd (%) for C18H34Cl2N2O13Pt·2H2O
(788.5): C 27.42, H 4.86, N 3.55; found: C 27.28, H 4.88, N 3.56.
Dichloro [methyl a-d-mannopyranosyl-(1!3)-2,4-diamino-2,4-dideoxy-b-
d-xylopyranosyl-(1!6)-a-d-mannopyranoside-N,N’] platinum (42): A so-
lution of K2[PtCl4] (28 mg, 68 mmol) in [D3]AcONa/D2O buffer (50 mm,
pH 7.0, 283 mL) was added at 308C to a stirred solution of compound 17
(33 mg, 68 mmol) in the same buffer (2334 mL). The reaction was moni-
tored by optical rotation at intervals of 0.5 h. After 12 h, the solution was
passed through a column of SephadexG-15 ( 1 2.5”100 cm) to give 42
an amorphous solid; Rf = 0.15 (ethyl acetate/MeOH/H2O 5:3:1), [a]D25
+37.1 (c = 0.46 in H2O); 1H NMR (400 MHz, D2O, 30 8C, DHO): d =
=
3
3
5.04 (d, J1,2 = 1.7 Hz, 1H; H1’’), 4.90 (d, J1,2 = 3.1 Hz, 1H; H1), 4.87
(brs, 1H; H1’), 4.30–4.28 (m, 2H; H3’, H5a’), 4.13 (m, 1H; H5), 3.99
3
3
3
(dd, J3,4 = 2.4, J4,5 = 1.2 Hz, 1H; H4), 4.04 (dd, J2,3 = 3.4 Hz, 1H;
H2’’), 3.99 (dd, J5,6a = 5.5, J6a,6b = 10.7 Hz, 1H; H6a), 3.95–3.86 (m,
5H; H2, H3, H3’’, H5’’, H6a’’), 3.80 (dd, J5,6b = 6.3, J6a,6b = 11.9 Hz,
1H; H6b’’), 3.75 (dd, J5,6b = 6.8 Hz, 1H; H6b), 3.73 (t, J3,4
9.8 Hz, 1H; H4’’), 3.63 (m, 1H; H4’), 3.62 (dd, J1,2 = 1.6, J2,3 = 3.6 Hz,
1H; H2’), 3.57 (brd, J5a,5b
3
2
3
2
3
3
(11 mg, 21%) as a pale yellow solid: m.p. 2708C (decomp); [a]D30
+10.8 (c = 0.54 in H2O); 1H NMR (400 MHz, D2O, 30 8C, DHO): d =
=
=
3J4,5
=
3
3
3
3
=
11.8 Hz, 1H; H5b’) ppm; 13C NMR
2
5.06 (d, J1,2
= 1.7 Hz, 1H; H1’’), 5.02 (s, 1H; H1’), 4.88 (d, J1,2 =
3
2
1.8 Hz, 1H; H1) 4.49 (dd, J4,5a = 1.9, J5a,5b = 13.2 Hz, 1H; H5a’), 4.16
(67.8 MHz, D2O, 30 8C, acetone): d = 161.6 (C=O), 103.2 (C1’), 102.1
(C1), 101.9 (C1’’), 75.8, 73.1, 72.0, 70.6 (C2, C3, C3’’, C5’’), 72.7 (C2’’),
71.9 (C4), 71.6 (C5), 70.0 (C3’), 69.8 (C6), 69.3 (C4’’), 63.5 (C6’’), 62.4
(C5’), 57.9 (OCH3), 51.1 (C2’), 48.3 (C4’) ppm; HRMS (ESI): calcd for
C19H33N2O14 [M+H]+: 513.1932; found 513.1938.
2
(d, J6a,6b = 10.7 Hz, 1H; H6a), 4.07–4.06 (m, 2H; H2, H2’’), 4.02 (dd,
3J5,6a = 1.4, J6a,6b = 11.4 Hz, 1H; H6a’’), 3.95 (dd, J2,3 = 3.4, J3,4
=
2
3
3
9.3 Hz, 1H; H3’’), 3.92–3.77 (m, 8H; H2, H3, H5, H6a, H2’, H3’, H5’’,
3
H6b’’), 3.74 (t, J3,4
=
3J4,5 = 9.4 Hz, 1H; H4’’), 3.54 (s, 3H; OCH3), 2.91
(m, 2H; H2’, H4’) ppm; 13C NMR (100.6 MHz, D2O, 30 8C, acetone): d =
101.5 (C1), 99.5 (C1’’), 98.0 (C1’), 74.3 (C5’’), 72.1 (C4), 71.1 (C3), 71.1
(C3’), 70.9 (C3’’), 70.6 (C2), 70.4 (C2’’), 68.5 (C6), 67.5 (C5), 67.4 (C4’’),
61.7 (C6’’), 56.7 (C5’), 55.5 (OCH3), 49.3 (C2’), 45.5 (C4’) ppm; HRMS
(ESI): calcd for C18H3435Cl2N2O13K195Pt [M+K]+: 790.0723; found
790.0724.
General method of determining the first order rate constants for Pt com-
plex formations: The first order rate constants, k (sꢀ1), were calculated by
fitting the processed data from the optical rotation measurement to
Equation (1):
ln ½sugarŠ=½sugarŠ ¼ ꢀkt=3600
ð1Þ
0
Dichloro [methyl a-d-mannopyranosyl-(1!3)-2,4-diamino-2,4-dideoxy-b-
d-xylopyranosyl-(1!2)-a-d-mannopyranoside-N,N’] platinum (43): A so-
lution of K2[PtCl4] (29 mg, 69 mmol) in [D3]AcONa/D2O buffer (50 mm,
pH 7.0, 285 mL) was added at 308C to a stirred solution of compound 23
(33 mg, 69 mmol) in the same buffer (2348 mL). The reaction was moni-
tored by optical rotation (2.0 mL aliquots) at intervals of 0.5 h. After
12 h, the solution was passed through a column of SephadexG-15 ( 1
where [sugar] is the concentration (mm) of a sugar at t h and [sugar]0 is
the concentration (mm) of the sugar at 0 h. [sugar] is calculated from
Equation (2):
½sugarŠ ðmmÞ ¼ 26 ꢂ ðaobsꢀa12 hÞ=a0 hꢀa12 h
Þ
ð2Þ
Chem. Eur. J. 2005, 11, 6478 – 6490
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
6489

H. Yuasa et al.
2.5”100 cm) to give 43 (25 mg, 49%) as a pale yellow solid: Rf 0.39
(iPrOH/H2O/NH4OH 7:3:1); m.p. 2558C (decomp); [a]3D0 = ꢀ17.2 (c =
1.09 in H2O); 1H NMR (400 MHz, D2O, 30 8C, DHO): d = 5.12 (s, 1H;
H1’), 5.08 (d, 3J1,2 = 1.6 Hz, 1H; H1’’), 4.97 (brs, 1H; H1), 4.67 (dd, 3J4,5a
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2
3
3
= 1.8, J5a,5b = 13.2 Hz, 1H; H5a’), 4.17 (dd, J1,2 = 1.6, J2,3 = 3.6 Hz,
3
1H; H2), 4.07 (dd, J2,3 = 3.4 Hz, 1H; H2’’), 4.04–3.99 (m, 3H; H3, H6a,
3
H6a’’), 3.96 (dd, J3,4 = 9.5 Hz, 1H; H3’’), 3.91–3.73 (m, 8H; H4, H5,
H6b, H3’, H5b’, H4’’, H5’’, H6b’’), 3.54 (s, 3H; OCH3), 2.92 (m, 2H; H2’,
H4’) ppm; 13C NMR (100.6 MHz, D2O, 30 8C, acetone): d = 100.0 (C1),
98.5 (C1’’), 95.6 (C1’), 75.1 (C2), 74.2, 73.6, 71.5, 70.2, 61.7, 61.5 (C3, C4,
C5, C6, C3’, C4’’, C5’’, C6’’), 71.1 (C3’’), 70.7 (C2’’), 56.9 (C5’), 55.5
(OCH3), 49.4 (C2’), 45.9 (C4’) ppm; HRMS (ESI): calcd for
C18H3435Cl2N2O13K195Pt [M+K]+: 790.0723; found 790.0674; elemental
analysis calcd (%) for C18H34Cl2N2O13Pt·2H2O (788.5): C 27.42, H 4.86, N
3.55; found: C 27.09, H 4.87, N 3.56.
Dichloro [methyl a-d-mannopyranosyl-(1!3)-2,4-diamino-2,4-dideoxy-b-
d-xylopyranosyl-(1!6)-a-d-galactopyranoside-N,N’] platinum (44): A so-
lution of K2[PtCl4] (29 mg, 69 mmol) in [D3]AcONa/D2O buffer (50 mm,
pH 7.0, 286 mL) was added at 308C to a stirred solution of compound 31
(34 mg, 69 mmol) in the same buffer (2339 mL). The reaction was moni-
tored by optical rotation at an interval of 0.5 h. After 12 h, the solution
was passed through a column of SephadexG-15 ( 1 = 2.5”100 cm) to
give 44 (31 mg, 60%) as a pale yellow solid: m.p. 2708C (decomp); [a]D30
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=
+16.4 (c = 1.57 in H2O); 1H NMR (400 MHz, D2O, 30 8C, DHO):
3
3
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d = 5.08 (d, J1,2 = 1.6 Hz, 1H; H1’’), 5.04 (s, 1H; H1’), 4.97 (d, J1,2
2.9 Hz, 1H; H1), 4.45 (dd, J4,5a = 1.9, J5a,5b = 11.6 Hz, 1H; H5a’), 4.19
(t, J = 6.6 Hz, 1H; H5), 4.13 (s, 1H; H4), 4.09 (dd, J5,6a = 5.1, J6a,6b
10.5 Hz, 1H; H6a), 4.05 (dd, J2,3 = 3.2 Hz, 1H; H2’’), 4.02 (dd, J5,6a
=
3
2
3
3
2
=
3
3
=
2
1.5, J6a,6b = 11.7 Hz, 1H; H6a’’), 3.99–3.96 (m, 2H; H2, H3), 3.90–3.57
(m, 7H; H6b, H3’, H5b’, H3’’, H4’’, H5’’, H6b’’), 3.55 (s, 3H; OCH3),
2.93 (s, 1H; H4’), 2.91 (s, 1H; H2’) ppm; 13C NMR (100.6 MHz, D2O,
308C, acetone): d = 100.2 (C1), 99.7 (C1’’), 97.8 (C1’), 74.2 (C5’’), 71.4
(C3’), 71.0 (C3’’), 70.6 (C2’’), 70.1, 70.0 (C2, C4), 69.6 (C5), 68.7 (C3),
67.8 (C6), 67.4 (C4’’), 61.7 (C6’’), 56.7 (C5’), 55.9 (OCH3), 49.2 (C2’), 45.6
(C4’) ppm; HRMS (ESI): calcd for C18H3435Cl2N2O13K195Pt [M+K]+:
790.0723; found 790.0649.
Acknowledgements
This work was supported by a grant from the 21 st Century COE Pro-
gram and a Grant-in-Aid for Scientific Research (No. 13680668) from the
Japanese Ministry of Education, Culture, Sports, Science and Technology.
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Received: January 27, 2005
Revised: May 31, 2005
Published online: August 11, 2005
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