Synthesis of Tethered Trisaccharides to Probe Inter-Saccharide Flexibility in Carbohydrate - Protein Interactions

Article abstract of DOI:10.1021/jo9806097

Two crystal structures of the trisaccharide epitope α-D-Galp(1→2)[α-D-Abep(1→3)α-D-Manp1→OCH ₃ 1 bound to antibody Fab and single-chain Fv fragments have been used to guide the design of an intramolecular tether that constrains the trisaccharid

Full text of DOI:10.1021/jo9806097

6288
J . Org. Chem. 1998, 63, 6288-6301
Syn th esis of Teth er ed Tr isa cch a r id es To P r obe In ter -Sa cch a r id e
F lexibility in Ca r boh yd r a te-P r otein In ter a ction s
Ramon Alibe´s and David R. Bundle*,†
Department of Chemistry, The University of Alberta, Edmonton, T6G 2G2, AB, Canada
Received April 2, 1998
Two crystal structures of the trisaccharide epitope R-D-Galp(1f2)[R-D-Abep(1f3)R-D-Manp1fOCH3
1 bound to antibody Fab and single-chain Fv fragments have been used to guide the design of an
intramolecular tether that constrains the trisaccharide ligand to conformations close to those of
the bound state. Preorganization of the ligand should overcome entropic penalties to binding and
provide enhanced affinity. Three tethers [O(CH2)nO, n ) 6, 7, and 8] were used to anchor the
solvent-exposed C6 atoms of the mannose and galactose residues. Two synthetic schemes were
employed. The first utilized an ethyl 1-thiogalactoside bearing the tether protected as a trityl ether
6-8. Glycosylation of the mannopyranoside 5 that contains a methanesulfonate at C6 by any of
the donors 6-8 afforded disaccharides 37-39. Subsequent removal of the trityl group allowed an
alkoxide to be generated on the ω-hydroxyl group of the tether for displacement of the sulfonate in
38% yield. By comparison when a ω-methanesulfonyloxy tether was incorporated as the mannoside
9, the disaccharide product 52 after reaction with the galactosyl donor 10 was converted to the
macrocycle 4 in 61% yield. The 3,6-dideoxy-xylo-hexopyranose residue was introduced by thiogly-
coside chemistry to yield the protected, tethered trisaccharide target molecules 49-51, which were
deprotected in a single hydrogenation step. Solid-phase enzyme immunoassays showed the tethered
trisaccharides 2-4 to be weaker inhibitors than trisaccharide 1 (+0.2-0.3 kcal mol-1). This suggests
that preorganization of oligosaccharides provides negligible gains in binding affinity.
In tr od u ction
ies that are several orders of magnitude higher than
those observed for sugars. There is evidence to suggest
that when oligosaccharides are part of larger macromol-
ecules, interactions between protein receptors and oli-
gosaccharide exhibit higher intrinsic affinity.4 The in-
crease in univalent association could arise through
preorganization of the oligosaccharide via steric factors
and protein-oligosaccharide interactions inherent to
each glycoprotein.14 Since low molecular weight oligosac-
charides or molecules derived from them are potential
candidates for therapeutic intervention in cell-cell
interactions,15-17 it is of considerable interest to probe
the effect of restricted oligosaccharide flexibility on the
association between ligand-protein complexes of known
structure. For example, is it possible to significantly
increase affinity by reducing interresidue flexibility so
that the oligosaccharide ligand is preorganized in its
bound state, thereby avoiding entropic losses that arise
from freezing-out a small set of bound conformers from
To assess the effect of interresidue flexibility on the
free energy of association between oligosaccharides and
their protein receptors, a series of tethered trisaccharides
has been designed and synthesized. The model system
selected is based upon a monoclonal antibody-trisaccha-
ride complex for which several protein crystal structures
are available.1-3 This structural detail simplifies the
selection of solvent-exposed portions of the saccharide
that avoid contact with the protein surface and hence are
suitable sites for tethering.
Carbohydrate-protein interactions are notable for the
weak affinity that characterizes association between
oligosaccharides and lectins,4-7 antibodies,8,9 and en-
zymes.10,11 Other small ligands such as steroids12 and
peptides13 exhibit KA values for their respective antibod-
† Phone: 403-492-8808.Fax: 403-492-7705.E-mail: dave.bundle@ualberta.ca.
(1) Cygler, M.; Rose, D. R.; Bundle, D. R. Science 1991, 253, 442-
446.
(2) Bundle, D. R.; Baumann, H.; Brisson, J .-R.; Gagne, S. M.;
Zdanov, A.; Cygler, M. Biochemistry 1994, 33, 5183-5192.
(3) Zdanov, A.; Li, Y.; Bundle, D. R.; Deng, S.-J .; MacKenzie, C. R.;
Narang, S. A.; Young, N. M.; Cygler, M. Proc. Natl. Acad. Sci. U.S.A.
1994, 91, 6423-6427.
(4) Carver, J . P.; Michnick, S. W.; Imberty, A.; Cumming, D. A. In
Carbohydrate Recognition in Cellular Function; Ciba Foundation
Symposium; Wiley: Chichester, 1989; Vol. 145, pp 6-26.
(5) Lemieux, R. U.; Delbaere, L. T. J .; Beierbeck, H.; Spohr, U. In
Host-Guest Molecular Interactions: From Chemistry to Biology, Ciba
Foundation Symposium; Wiley: Chichester, 1991; Vol. 158, pp 231-
248.
(6) Lemieux, R. U. Acc. Chem. Res. 1996 29, 373-380.
(7) Isbister, B. D.; St. Hilaire, P. M.; Toone, E. J . J . Am. Chem. Soc.
1995, 117, 12877-12878.
(8) Lemieux, R. U. Chem. Soc. Rev. 1989, 18, 347-374.
(9) Bundle, D. R., Altman, E., Auzanneau, F.-I., Baumann, H.,
Eichler, E., & Sigurskjold, B. W. In Complex Carbohdrates in Drug
Research, Alfred Benzon Symposium No. 36; Bock, K., Clausen, H.,
Eds.; Munksgaard: Copenhagen, 1994.
(10) Watson, K. A., Mitchell, E. P., J ohnson, L. N., Son, J . C.,
Bichard, C. J . F., Orchard, M. G., Fleet, G. W. J ., Oikonomakos, N.
G., Leonidas, D. D., Kontou, M., Papageorgioui, A. Biochemistry 1994,
33, 5745-5758.
(11) Lindh, I.; Hindsgaul, O. J . Am. Chem. Soc. 1991, 113, 216-
223.
(12) Arevalo, J . H.; Stura, E. A.; Taussig, M. J .; Wilson, A. I. J . Mol.
Biol. 1993, 231, 103-118.
(13) Stanfield, R. L.; Wilson, I. A. Curr. Opin. Struct. Biol. 1995, 5,
103-113.
(14) Stuike-Prill, R., Meyer, B. Eur. J . Biochem. 1990, 194, 903-
919.
(15) Kolb, H. C.; Ernst, B. Chem. Eur. J . 1997, 3, 1571-1578. Wong,
H. C.; Moris-Varas, F.; Hung, S.-C.; Marron, T. G.; Lin, C.-C.; Gong,
K. W.; Weitz-Schmidt, G. J . Am. Chem. Soc. 1997, 119, 8152-8158.
(16) Heerze, L. D., Kelm, M. M, Talbot, J . A. Armstrong, G. D. J .
Infect. Dis. 1994, 169, 1291-1296. Hansen, H. C., Haataja, S., Finne,
J .; Magnusson, G. J . Am. Chem. Soc. 1997, 119, 6974-6979.
(17) McAuliffe, J . C.; Hindsgaul, O. Chem. Ind. 1997, 5, 170-174.
S0022-3263(98)00609-4 CCC: $15.00 © 1998 American Chemical Society
Published on Web 08/07/1998

Synthesis of Tethered Trisaccharides
J . Org. Chem., Vol. 63, No. 18, 1998 6289
Ch a r t 1
F igu r e 1. (A) A direct Abe O-2 to Gal O-2 hydrogen bond was
observed in the crystal structure of Se155.4 antibody complex
with trisaccharide 12. (B) When trisaccharide 1 was crystal-
lized with a single chain antibody, the oligosaccharide forms
a Abe O-2 to Gal O-2 hydrogen bond bridged by a water
molecule.
the large number of conformational families that are
sampled by typical oligosaccharides?
A large, favorable enthalpy of association compensated
by unfavorable entropy observed for lectin-oligosaccha-
ride complex formation is cited as supporting evidence
for the dominant role of inter-saccharide flexibility as a
determinant of weak sugar-protein binding constants.4,18
The entropic barrier associated with the loss of degrees
of freedom when an oligosaccharide binds to a protein
receptor has been estimated to be as large as 1-2 kcal
mol-1 for each glycosidic torsional angle immobilized.18
Estimates from other work suggest values in the range
∼0.6 kcal mol-1 per torsion angle.19,20 On the basis of
the results of extensive molecular recognition studies for
a large number of lectins and antibodies, Lemieux has
suggested that enthalpy-entropy compensation has its
origins in solvation effects at polyamphiphilic surfaces.5,6
Support for this interpretation has come from thermo-
dynamic solvent isotope effects determined by titration
microcalorimetry.21
To probe the entropic barrier resulting from flexibility
about glycosidic bonds and to place an empirical estimate
on its cost to overall free energy of association, it is
necessary to synthesize a relatively rigid oligosaccharide.
Ideally such a derivative would preserve the enthalpic
stabilization while reducing the entropic barrier. This
could be accomplished by reducing interresidue flexibility
with a tether that avoids contact with the protein surface
and maintains the distribution of three-dimensional
structures to sets that populate the conformation of the
bound state. We realized that the structure of the
complex between monoclonal antibody Se-155.4 and its
trisaccharide ligand 1 were ideally suited to this purpose
since the conformation in the bound state places the
primary hydroxyl groups of the partially solvent-exposed
galactose and mannose residues in positions that are both
solvent exposed and well removed from the protein
surface (Figure 1). Trisaccharide 1 has been observed
in one of two bound conformations, 1-A and 1-B, which
correspond to the interatomic distances Man O-6 to Gal
O-6 of 7.5 and 5.7 Å, respectively. To satisfy these
distance constraints as well as preserve the interresidue
distances between the abequose and galactose residues,
three tethered trisaccharide 2-4 were selected as targets
for synthesis. The synthesis and characterization of
these molecules is reported here, together with binding
data from a solid-phase assay.
Resu lts
Str a tegy. Retrosynthetic analysis suggested the use
of the multifunctionalized monosaccharide 5 and the
galactose synthons 6-8 to construct tethered disaccha-
rides enroute to the target trisaccharides 2-4 (Chart 1).
The mannose acceptor 5 contains a good leaving group
at the exocyclic C-6 atom for attack by the alkoxide of
the tether, that is preassembled as part of the galactosyl
(18) Carver, J . P. Pure Appl. Chem. 1993, 65, 763-770.
(19) Finkelstein, A. V.; J anin, J . Protein Eng. 1989, 3, 1-3.
(20) Searle, M. S.; Williams, D. H. J . Am. Chem. Soc. 1992, 114,
10690-10697.
(21) Chervenak, M. C.; Toone, E. J . J . Am. Chem. Soc. 1994, 116,
10533-10539.

6290 J . Org. Chem., Vol. 63, No. 18, 1998
Alibe´s and Bundle
Ch a r t 2
F igu r e 3. Conditions: (a) TBAF, THF, 86%; (b) 18, NaH,
THF, 65 °C, 84%; (c) TSA, MeOH:EtOAc (9:1), 48 h, 80%; (d)
Bu2SnO, Bu4NI, AllBr, 70%; (e) MsCl, pyridine, CH2Cl2, 73%.
acetonide23 21 was first protected as its tert-butyldiphe-
nylsilyl ether 22 and then benzylated under standard
conditions to give 23.24 Treatment with aqueous acetic
acid followed by regioselective allylation employing dibu-
tyltin oxide25 afforded the selectively protected alcohol
25 via the diol 24. Temporary protection at O-2 was
achieved by acetylation (26), followed by cleavage of the
silyl ether (27), and then methanesulfonylation provided
the fully protected monosaccharide 28. Transesterifica-
tion gave the selectively protected glycoside 5, which
functions as an acceptor to the glycosyl donors 6-8.
By converting 23 to the primary alcohol derivative 29,
the alternate glycosyl acceptor 9 may be accessed in five
steps (Figure 3). Alkylation of the primary alcohol with
18 introduced the tether protected as its trityl ether 30.
The isopropylidene and trityl groups were cleaved by
treatment of 30 with p-toluenesulfonic acid at room
temperature. The resulting triol 31 was reacted with
dibutyltin oxide in methanol, and the intermediate
stannane was regioselectively alkylated by allyl bromide
in the presence of tetrabutylammonium iodide25 to afford
the diol 32. The primary alcohol moiety of 32 was
selectively esterified to give the glycosyl acceptor 9.
The three galactosyl donors 6-8 each with a different
sized tether attached at O-6 were prepared starting from
the ethyl 1-thiogalactopyranoside 3326 (Figure 4). Pro-
tection of the primary hydroxyl group as its tert-butyl-
diphenylsilyl ether 34 followed by per-O-benzylation and
hydrolysis of the silyl ether 35 gave the tri-O-benzylated
thioglycoside 36. Hexane, heptane, and octane diols were
first converted to the monotrityl ethers 13,27 14, 15.28
These were then derivatized as the corresponding ω-trityl
methanesulfonates 16-18. Alkylation of 36 by the
F igu r e 2. Conditions: (a) t-BuPh2SiCl, DMAP, CH2Cl2, 93%;
(b) BnBr, NaH, DMF, 84%; (c) aq, 80%, HOAc, 84%; (d) Bu2-
SnO, Et4NI, AllBr, 92%; (e) Ac2O, pyridine, 84%; (f) TBAF,
THF, 85%; (g) MsCl, pyridine, CH2Cl2, 88%; (h) NaOMe,
MeOH, 95%.
donors 6-8. An alternative approach reverses the posi-
tions of the leaving group and nucleophile so that the
leaving group is placed on the tether as part of the
mannose glycoside 9. The corresponding galactose syn-
thon 10 would then provide an alkoxide nucleophile after
glycosylation of 9 and selective deprotection steps of the
intermediate disaccharide. In both instances the six,
seven, and eight carbon tethers could be accessed from
the corresponding diols protected as their ω-trityl meth-
anesulfonates 16-18 (Chart 2). The final steps of either
approach involve selective deprotection of the allyl ether
of a tethered disaccharide and reaction with 3,6-dideoxy-
hexose donor 11.22 A less hydrophobic tether based on
triethylene glycol was envisaged, and for this purpose the
galactosyl donor 12 could be synthesized following an
approach similar to that used to synthesize compounds
6-8.
(23) Evans, M. E.; Parrish, F. W. Carbohydr. Res. 1977, 54, 105-
114.
(24) Khan, S. H.; Abbas, S. A.; Matta, K. Carbohydr. Res. 1990, 205,
385-397. Khan, S. H., Matta, K. Carbohydr. Res. 1993, 243, 29-42.
(25) Yang, G.; Kong, F.; Zhou, S. Carbohydr. Res. 1991, 211, 179-
182.
(26) Kaesbeck, L.; Kessler, H. Liebigs Ann. Org. Bioorg. Chem. 1997,
1, 169-174.
(27) Kaats-Richter, V. E. M.; Zwikker, J . W.; Keegstra, E. M. D.;
J enneskens, L. W. Synth. Commun. 1994, 24, 2399-2410.
(28) Wong, J . Y.; Leznoff, C. C. Can. J . Chem. 1973, 51, 2452-2456.
P r ep a r a tion of Mon osa cch a r id e Bu ild in g Block s.
The selectively protected acetonide 23 was a common
starting point for the high-yield syntheses of the mannose
synthons 5 and 9 (Figures 2 and 3). The readily prepared
(22) Lowary, T.; Eichler, E.; Bundle, D. R. J . Org. Chem. 1995, 60,
7316-7327.

Synthesis of Tethered Trisaccharides
J . Org. Chem., Vol. 63, No. 18, 1998 6291
aqueous solution of mercuric chloride. Each of the
disaccharide alcohols 46-48 was isolated in ∼85% yield.
The abequose thioglycoside donor 11 was activated by
NIS/silver triflate, and the trisaccharides 49-51 were
isolated in 54-62% yields (Figure 5). Deprotection of the
tethered trisaccharides was accomplished in a single
hydrogenation step to yield 2-4 (Figure 7).
Attempts to tether the disaccharide by a triethylene
glycol spacer were unsuccessful. The galactosyl donor
12 was used to successfully glycosylate the mannopyra-
noside alcohol 5 under conditions similar to those em-
ployed for the synthesis of 39. The trityl ether of the
resulting disaccharide 54 was selectively cleaved to give
the alcohol 55. However, reaction of 55 under the basic
conditions employed to yield the macrocycles 43-45
failed to yield the tethered disaccharide target molecule
(Figure 8). The failure of this reaction is attributed to
the strong preference of the triethylene glycol tether for
syn clinal conformers about the C-C bonds linking
oxygen heteroatoms. Several torsional angles in the
tether have to adopt near eclipsed conformations in order
to close the macrocycle, and this presumably provides a
sufficiently elevated energy barrier to the formation of
the tethered product from 55.
F igu r e 4. Conditions: (a) t-BuPh2SiCl, imidazole, DMF, 88%;
(b) NaH, BnBr, DMF, 74%; (c) TBAF, THF, 95%; (d) NaH,
THF, 16 (17 or 18), 85-91%; (e) NaH, THF, 20, 89%.
The stereochemistry of the newly formed glycosidic
bonds was conveniently established by proton homo-
nuclear 3J coupling constants. As both glycosyl donors
possessed the galacto configuration, the chemical shift
protected alkanediols yielded the respective six, seven,
and eight carbon ether derivatives 6-8. Triethylene
glycol was derivatized in fashion similar to give 2029 and
then the galactosyl donor 12 by reaction with the thioga-
lactoside 36. The 3,6-dideoxyhexose donor 11 was syn-
thesized from glucose according to a previously published
method.22
Assem bly of th e Teth er ed Tr isa cch a r id e. The
thiogalactoside 6 was activated in situ by N-iodosuccin-
imide/triflic acid in the presence of the selectively pro-
tected mannopyranoside 5 to give disaccharide 37 in 77%
yield (Figure 5). Cleavage of the trityl ether gave the
alcohol 40. Slow addition of the alcohol 40 to a boiling
mixture of sodium hydride and Cs2CO3 in THF resulted
in a 38% yield of the fully protected and tethered
disaccharide 43. An identical sequence of reactions was
employed to synthesize the disaccharides 44 and 45,
tethered by the C7 and C8 linkers. The yields of each
step were comparable to those obtained in the synthesis
of the C6-tethered disaccharide 43.
A more efficient synthesis of the tethered disaccharide
45 was accomplished by placing the leaving group on the
tether attached to the mannose residue and displacing
it with the alkoxide generated at C-6 of the galactose
residue (Figure 6). The 6-O-trityl galactosyl donor 10
reacted with the mannose alcohol 9 under NIS/triflic acid
activation to give the disaccharide 52. Removal of the
trityl ether gave the alcohol 53, and under reaction
conditions similar to those described to tether the dis-
accharides 40-42, this route resulted in a 61% yield of
the macrocycle 45. The approach was not applied to the
synthesis of 43 and 44 since there was insufficient
material available to complete the syntheses.
3
and J coupling constants unambiguously established the
R configuration of the Abe-Man and Gal-Man anomeric
linkages31 in the protected oligosaccharides. This was
confirmed for the tethered molecules 2-4 by the hetero-
1
nuclear J coupling constants at each anomeric center.32
A thorough NMR study of 2-4 by multidimensional NMR
methods established the assignment of all proton and
carbon-13 resonances prior to conformational analysis
employing NOE measurements and molecular dynamics
calculations.33 These studies showed that the tethers
succeeded in constraining the range of motions in com-
pounds 2-4 close to torsional angles found in the bound
conformer 1B (Figure 1).
Biologica l Activity. Affinity-purified Se-155.4 anti-
body absorbed to enzyme immunoassay microtiter plates
was allowed to compete for biotin-labeled polysaccharide
antigen34,35 in the presence and absence of inhibitors 1-4.
The inhibition data show that the inhibitory powers of
tethered trisaccharides 2-4 are comparable to but slightly
less than that of the native trisaccharide 1 (Figure 9).
Estimates of IC50 values for 2-4 suggest an approximate
free energy difference, ∆∆G ≈ 0.2-0.3 kcal mol-1 relative
to the reference trisaccharide 1. More precise calorimetry
data showed that the free energy difference ∆∆G ≈ 0.1
kcal mol-1 is even smaller.33
Discu ssion
The most serious obstacles to be overcome in the
generation of constrained epitopes is the avoidance of
(31) Bundle, D. R.; Lemieux, R. U. Methods Carbohydr. Chem. 1976,
7, 79-86.
(32) Bock, K.; Pederson, C. J . Chem. Soc., Perkin Trans. 2 1974,
293.
(33) Bundle, D. R.; Alibes, R.; Nilar, S.; Otter, A.; Warwas, M.;
Zhang, P. J . Am. Chem. Soc. 1998, 120, 5317-5318.
(34) Meikle, P. J .; Young, N. M.; Bundle, D. R. J . Immunol. Meth.
1990, 132, 255-261.
(35) Bundle, D. R.; Eichler, E.; Gidney, M. A. J .; Meldal, M.;
Ragauskas, A.; Sigurskjold, B. W.; Sinnott, B.; Watson, D. C.; Yaguchi,
M.; Young, N. M. Biochemistry 1994, 33, 5172-5182.
The three disaccharides 43-45 were selectively depro-
tected at O-3 of the mannose residue by a base-catalyzed
isomerization of the allyl ethers.30 The isopropenyl ether
intermediates were not isolated but hydrolyzed by an
(29) Altenburger, J .-M.; Lebeau, L.; Mioskowski, C.; Schirlin, D.
Helv. Chim. Acta 1992, 75, 2538-2544.
(30) Gigg, J .; Gigg, R. J . Chem. Soc. C 1966, 82-86.

6292 J . Org. Chem., Vol. 63, No. 18, 1998
Alibe´s and Bundle
F igu r e 5. Conditions: (a) NIS, TfOH, CH2Cl2, 77%; (b) TSA, MeOH/EtOAc, 85-87%; (c) NaH, Cs2CO3, THF, 85 °C, 34-38%; (d)
(i)KOtBu, DMSO, (ii) HgO, HgCl2, H2O, 85%; (e) 11, NIS, AgOTf, 4AMS, CH2Cl2, PhMe, 54-62%.
F igu r e 6. Conditions: (a) NIS, TfOH, CH2Cl2, 82%; (b) TSA,
MeOH/EtOAc, 81%; (c) NaH, Cs2CO3 THF, 85 °C, 61%.
F igu r e 8. Conditions: (a) NIS, TfOH, CH2Cl2, 74%; (b) TSA,
MeOH/EtOAc, 80%; (c) NaH, Cs2CO3, THF, 85 °C.
ies,36 enzymes,11 bacterial adhesins/toxins,37and lec-
F igu r e 7. Conditions: (a) H2, Pd/C, HOAc, 83-90%.
tins.38,39 Where binding has been measured, the improve-
ment in ∆G has been modest.11,36-38 The data for
steric clashes between the tether and protein binding site
trisaccharides 2-4 are consistent with these observations
and suggest that the preordering of glycosidic bond
conformation is an approach in the search for tight
binding sugar-based inhibitors, which by itself seems
unlikely to facilitate the design of carbohydrate-based
therapeutics.
and the fidelity with which the bound conformation is
reproduced. However, in the example reported here two
solved crystal structures of ligand-antibody complexes
ensured that the former was not an issue, while NMR
studies confirmed that the linkages adopted constrained
torsional angles that spanned those of the bound state.33
Several investigators have synthesized constrained oli-
gosaccharides to probe binding strength with antibod-
(37) Wilstermann, M.; Balogh, J .; Magnusson, G. J . Org. Chem.
1997, 62, 3659-3665.
(38) Kolb, H. C. Bioorg. Med. Chem. 1997, 7, 2629-2634.
(39) Navarre, N.; van Oijen, A. H.; Boons, G. J . Tetrahedron Lett.
1997, 38, 2023-2026.
(36) Kabat, E. A.; Liao, J .; Burzynska, M. H.; Wong, T. C.; Thøger-
son, H.; Lemieux, R. U. Mol. Immunol. 1981, 18, 873-881.

Synthesis of Tethered Trisaccharides
J . Org. Chem., Vol. 63, No. 18, 1998 6293
134.2, 128.3, 127.9, 127.8, 117.5, 100.2, 79.4, 74.9, 73.2, 70.8,
69.4, 69.0, 67.9, 54.9, 37.6; FABMS calcd for [C18H26O8SNa]
425.1, found 425.1. Anal. Calcd for C18H26O8S (402.46): C,
53.72; H, 6.51. Found: C, 53.34; H, 6.43.
Eth yl 2,3,4-Tr i-O-ben zyl-6-O-(6′-tr ityloxyh exyl)-1-th io-
r-D-ga la ctop yr a n osid e (6), Eth yl 2,3,4-Tr i-O-ben zyl-6-O-
(7′-tr ityloxyh eptyl)-1-th io-r-D-galactopyr an oside (7), Eth -
yl 2,3,4-Tr i-O-b en zyl-6-O-(8′-t r it yloxyoct yl)-1-t h io-r-D-
ga la ctop yr a n osid e (8), or Eth yl 2,3,4-Tr i-O-ben zyl-6-O-
(1′′,1′′,1′′-t r ip h e n y lo x y -3,6-d io x a o c t a n y l)-1-t h io -r-D -
ga la ctop yr a n osid e (12). To a solution of alcohol 36 (3.24
mmol) in dry THF (50 mL) was added NaH (10.4 mmol) under
an Ar atmosphere. After being stirred for 1 h at 50 °C, a
solution of 16, 17, 18, or 20 (5.62 mmol) in dry THF (8 mL)
was added dropwise. The reaction mixture was stirred at 65
°C for 18 h and cooled to room temperature, and excess NaH
was decomposed with MeOH. The solvent was evaporated
under reduced pressure, and the resulting residue was taken
up in CH2Cl2, washed with a saturated NaCl solution, and
dried over Na2SO4. The solvent was evaporated, and the
residue was purified by chromatography.
6: eluent 98:2 pentane-EtOAc; yield 89%; [R]D +77.7° (c
2.2, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.30-7.15 (m, 30H),
5.49 (d, 1H, J ) 5.5 Hz), 4.94 (d, 1H, J ) 11.5 Hz), 4.83 (d,
1H, J ) 11.8 Hz), 4.74 (d, 1H, J ) 11.7 Hz), 4.68 (d, 1H, J )
11.8 Hz), 4.67 (d, 1H, J ) 11.7 Hz), 4.59 (d, 1H, J ) 11.5 Hz),
4.26 (dd, 1H, J ) 9.9, 5.5 Hz), 4.22 (t, 1H, J ) 6.4 Hz), 3.88 (d,
1H, J ) 2.9 Hz), 3.79 (dd, 1H, J ) 9.9, 2.9 Hz), 3.44 (d, 2H, J
) 6.4 Hz), 3.35 (dt, 1H, J ) 9.3, 6.7 Hz), 3.27 (dt, 1H, J ) 9.3,
6.7 Hz), 3.02 (t, 2H, J ) 6.6 Hz), 2.55 (dq, J ) 7.4 Hz), 2.47
(dq, J ) 7.4 Hz), 1.59 (dt, 2H, J ) 6.9, 6.6 Hz), 1.48 (dt, 2H, J
F igu r e 9. Affinity-purified Se155.4 antibody was coated on
microtiter plates. Biotin-labeled O-polysaccharide antigen was
allowed to bind to antibody coated plates in the presence and
absence of inhibitors 1-4. Percentage inhibition is plotted
against molar concentration: trisaccharide 1, 0; trisaccharide
2, (; trisaccharide 3, O; trisaccharide 4, 2.
Exp er im en ta l Section
Optical rotations were measured with a polarimeter at 22
( 2 °C. TLC was performed on silica gel 60-F254 (E. Merck,
Darmstadt) with detection by quenching of fluorescence and/
or by charring with 5% sulfuric acid in ethanol. Iatrobeads
refers to a beaded silica gel 6RS-8060 manufactured by Iatron
Laboratories (Tokyo). All commercial reagents were used as
supplied, and chromatography solvents were distilled prior to
use. Column chromatography was performed on silica gel 60
(E. Merck 40-60 µM, Darmstadt) or Iatrobeads. 1H NMR
spectra were recorded either at 360 or at 500 MHz and are
referenced to either internal CHCl3 (δ 7.24, CDCl3) or internal
acetone (δ 2.225, D2O). 13C NMR spectra were recorded either
at 75.5 or at 125 MHz and are referenced to either internal
CHCl3 (δ 77.0, CDCl3) or internal acetone (δ 37.01, D2O). The
assignments of resonances for the target compounds 2-4 were
made by two-dimensional homonuclear and heteronuclear shift
correlation experiments. Organic solutions were dried prior
to concentration under vacuum at < 40 °C (bath). Microanaly-
ses were carried out by the analytical service at this depart-
ment, and all samples submitted for elemental analyses were
dried overnight under vacuum with phosphorus pentoxide at
56 °C (refluxing acetone). Fast atom bombardment mass
spectra were recorded on samples suspended in Cleland’s
matrix with xenon as the bombarding gas. Electrospray high-
resolution mass spectra (ES HRMS) were recorded on a
ZabSpecTOF mass spectrometer for aqueous solution of depro-
tected oligosaccharides.
) 7.2, 6.8 Hz), 1.40-1.25 (m, 4H), 1.24 (t, 3H, J ) 7.4 Hz); 13
C
NMR (75 MHz, CDCl3) δ 144.42, 138.75, 138.64, 138.24,
128.60, 128.24, 128.19, 128.11, 127.83, 127.61, 127.50, 127.44,
127.39, 126.74, 86.22, 83.18, 79.53, 76.18, 75.16, 74.72, 73.27,
72.36, 71.41, 69.53, 69.33, 63.48, 29.96, 29.62, 26.10, 25.97,
23.35, 14.62. Anal. Calcd for C54H60O6S (837.12): C, 77.48;
H, 7.22; S, 3.83. Found: C, 77.44; H, 7.11; S, 3.92.
7: eluent 98:2 pentane-EtOAc; yield 91%; [R]D +66.7° (c
0.7, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.30-7.15 (m, 30H),
5.49 (d, 1H, J ) 5.5 Hz), 4.94 (d, 1H, J ) 11.5 Hz), 4.82 (d,
1H, J ) 11.8 Hz), 4.74 (d, 1H, J ) 11.7 Hz), 4.68 (d, 1H, J )
11.8 Hz), 4.66 (d, 1H, J ) 11.7 Hz), 4.60 (d, 1H, J ) 11.5 Hz),
4.28 (dd, 1H, J ) 9.9, 5.5 Hz), 4.22 (t, 1H, J ) 6.4 Hz), 3.89 (d,
1H, J ) 2.9 Hz), 3.79 (dd, 1H, J ) 9.9, 2.9 Hz), 3.43 (d, 2H, J
) 6.4 Hz), 3.35 (dt, 1H, J ) 9.3, 6.8 Hz), 3.27 (dt, 1H, J ) 9.3,
6.7 Hz), 3.02 (t, 2H, J ) 6.6 Hz), 2.60 (dq, 1H, J ) 7.4 Hz),
2.48 (dq, 1H, J ) 7.4 Hz), 1.59 (dt, 2H, J ) 6.9 Hz), 1.46 (dt,
2H, J ) 6.7 Hz), 1.38-1.22 (m, 6H), 1.24 (t, 3H, J ) 7.4 Hz);
13C NMR (75 MHz, CDCl3) δ 144.40, 138.71, 138.61, 138.20,
128.57, 128.04, 128.16, 128.08, 127.80, 127.57, 127.47, 127.41,
127.36, 126.69, 86.17, 83.11, 79.46, 76.14, 75.10, 74.67, 73.22,
72.29, 71.41, 69.48, 69.30, 63.45, 29.89, 29.59, 29.24, 26.14,
25.98, 23.30, 14.59. Anal. Calcd for C55H62O6S (851.15): C,
77.61; H, 7.34; S, 3.77. Found: C, 77.61; H, 7.34; S, 3.95.
8: eluent 98:2 pentane-EtOAc; yield 85%; [R]D +77.6° (c
0.8, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.30-7.15 (m, 30H),
5.47 (d, 1H, J ) 5.5 Hz), 4.93 (d, 1H, J ) 11.5 Hz), 4.81 (d,
1H, J ) 11.9 Hz), 4.73 (d, 1H, J ) 11.7 Hz), 4.68 (d, 1H, J )
11.8 Hz), 4.66 (d, 1H, J ) 11.7 Hz), 4.58 (d, 1H, J ) 11.5 Hz),
4.27 (dd, 1H, J ) 9.9, 5.5 Hz), 4.23 (t, 1H, J ) 6.5 Hz), 3.89 (d,
1H, J ) 2.9 Hz), 3.78 (dd, 1H, J ) 9.9, 2.9 Hz), 3.44 (d, 2H, J
) 6.5 Hz), 3.35 (dt, 1H, J ) 9.2, 6.6 Hz), 3.27 (dt, 1H, J ) 9.2,
6.7 Hz), 3.02 (t, 2H, J ) 6.6 Hz), 2.60 (dq, 1H, J ) 4 Hz), 2.48
(dq, 1H, J ) 7.4 Hz), 1.59 (dt, 2H, J ) 6.9 Hz), 1.46 (dt, 2H, J
) 6.7 Hz), 1.38-1.22 (m, 8H), 1.24 (t, 3H, J ) 7.4 Hz); 13C
NMR (75 MHz, CDCl3) δ 144.40, 138.71, 138.61, 138.20,
128.57, 128.18, 128.13, 128.06, 127.80, 127.45, 127.39, 127.33,
126.67, 86.17, 83.11, 79.46, 76.14, 75.10, 74.66, 73.20, 72.29,
71.41, 69.48, 69.30, 63.49, 29.91, 29.59, 29.33, 29.28, 26.10,
25.96, 23.29, 14.56. Anal. Calcd for C56H64O6S (865.18): C,-
77.74; H, 7.46; S, 3.71. Found: C, 77.53; H, 7.46; S, 3.87.
12: eluent 1:1 pentane-EtOAc; yield 89%; [R]D +66.3° (c
0.8, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.30-7.20 (m, 30H),
5.48 (d, 1H, J ) 5.5 Hz), 4.95 (d, 1H, J ) 11.5 Hz), 4.86 (d,
Solid-phase immunoassay (EIA) was performed as previ-
ously described.34,35 The data were plotted with Origin soft-
ware (Microcal Software, Northampton, MA).
Meth yl 3-O-Allyl-4-O-ben zyl-6-O-m eth a n esu lfon yl-r-D-
m a n n op yr a n osid e (5). Compound 28 (4.21 g, 9.48 mmol)
was dissolved in dry methanol (30 mL), a small piece of sodium
was added, and the reaction was stirred overnight. The
solution was neutralized and concentrated, and the residue
was purified by chromatography (1:1 EtOAc-pentane) to
afford 5 (4.21 g, 95%) as an oil: [R]D +84.5° (c 1.6, CHCl3); 1H
NMR (360 MHz, CDCl3) δ 7.32 (m, 5H), 5.91 (ddd, 1H, J )
17.2, 10.4, 5.7 Hz), 5.31 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.21
(ddd, 1H, J ) 10.4, 3.1, 1.3 Hz), 4.87 (d, 1H, J ) 10.8 Hz),
4.74 (d, 1H, J ) 1.7 Hz), 4.61 (d, 1H, J ) 10.8 Hz), 4.47 (dd,
1H, J ) 11.2, 1.7 Hz), 4.39 (dd, 1H, J ) 11.2, 3.7 Hz), 4.18
(dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.12 (dddd, 1H, J ) 12.6,
5.6, 1.6, 1.3 Hz), 3.99 (dd, 1H, J ) 2.5, 1.7 Hz), 3.75 (m, 3H),
3.35 (s, 3H), 3.05 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 137.8,

6294 J . Org. Chem., Vol. 63, No. 18, 1998
Alibe´s and Bundle
1
1H, J ) 12.1 Hz), 4.78 (d, 1H, J ) 10.5 Hz), 4.72 (d, 1H, J )
12.1 Hz), 4.68 (d, 1H, J ) 10.5 Hz), 4.60 (d, 1H, J ) 11.5 Hz),
4.28 (dd, 1H, J ) 9.9, 5.5 Hz), 4.27 (t, 1H, J ) 6.4 Hz), 3.91 (d,
1H, J ) 2.8 Hz), 3.79 (dd, 1H, J ) 9.9, 2.8 Hz), 3.70-3.55 (m,
9H), 3.51 (d, 2H, J ) 6.4 Hz), 3.48 (m, 1H), 3.22 (t, 2H, J )
5.3 Hz), 2.52 (dq, 1H, J ) 7.4 Hz), 2.48 (dq, 1H, J ) 7.4 Hz),
1.24 (t, 1H, J ) 7.4 Hz); 13C NMR (75 MHz, CDCl3) δ 144.1,
138.75, 138.6, 138.2, 128.6, 128.2, 128.2, 128.1, 127.8, 127.7,
127.5, 127.5, 127.4, 126.8, 86.5, 83.2, 79.5, 76.1, 74.9, 74.7, 73.2,
72.3, 70.7, 70.6, 70.62, 70.5, 69.8, 69.4, 63.2, 23.4, 14.6. Anal.
Calcd for C54H60O8S (869.12): C, 74.63; H, 6.96; S, 3.69.
Found: C, 74.64; H, 7.08; S, 3.87.
Meth yl 3-O-Allyl-4-O-ben zyl-6-O-(8′-m eth a n esu lfoxy-
octyl)-r-D-m a n n op yr a n osid e (9). To an ice-cooled solution
of 32 (595 mg, 1.31 mmol) and dry pyridine (1 mL) in dry CH2-
Cl2 (14 mL) was added methanesulfonyl chloride (122 µL, 1.57
mmol) dropwise. The mixture was stirred overnight as it came
to room temperature. The mixture was diluted with CH2Cl2,
washed successively with 1 M HCl and a saturated NaCl
solution, and dried (Na2SO4). Evaporation of solvent and
chromatography (1:1 EtOAc-pentane) gave 9 (513 mg, 73%)
as an oil: [R]D +53.5° (c 2.1, CHCl3); 1H NMR (360 MHz,
CDCl3) δ 7.35-7.25 (m, 5H), 5.92 (ddd, 1H, J ) 17.2, 10.4, 5.7
Hz), 5.30 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.17 (ddd, 1H, J )
10.4, 3.1, 1.3 Hz), 4.83 (d, 1H, J ) 11.0 Hz), 4.75 (d, 1H, J )
1.6 Hz), 4.57 (d, 1H, J ) 11.0 Hz), 4.18 (t, 2H, J ) 6.6 Hz),
4.17 (m, 1H), 4.11 (dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 3.96
(m, 1H), 3.75 (dd, 1H, J ) 8.7, 8.7 Hz), 3.71 (dd, 1H, J ) 8.7,
3.0 Hz), 3.68-3.59 (m, 3H), 3.50 (dt, 1H, J ) 9.3, 6.5 Hz), 3.39
(dt, 1H, J ) 9.2, 6.7 Hz), 3.33 (s, 3H), 2.45 (s, 1H, J ) 2.6 Hz),
1.65-1.55 (m, 4H), 1.25 (m, 8H); 13C NMR (75 MHz, CDCl3) δ
138.4, 134.4, 128.1, 127.6, 127.4, 117.0, 100.1, 79.5, 74.7, 74.1,
71.3, 70.6, 70.5, 69.8, 69.5, 68.2, 54.5, 37.0, 29.2, 28.9, 28.8,
28.6, 25.7, 25.1. Anal. Calcd for C26H42O9S (530.67): C, 58.85;
H, 7.98; S, 6.04. Found: C, 58.86; H, 8.01; S, 6.17.
15:28 eluent 4:1 pentane-EtOAc; yield 55%; H NMR (360
MHz, CDCl3) δ 7.55-7.15 (m, 15H), 3.52 (t, 2H, J ) 6.4 Hz),
3.05 (t, 2H, J ) 6.2 Hz), 1.63 (dt, 2H, J ) 6.3 Hz), 1.55 (dt,
2H, J ) 6.4 Hz) 1.45-1.20 (m, 9H). Anal. Calcd for C27H32O2
(388.24): C, 83.45; H, 8.31. Found: C, 83.89; H, 8.16.
19: eluent 1:1 pentane-EtOAc; yield 49%; 1H NMR (360
MHz, CDCl3) δ 7.50-7.18 (m, 15H), 3.72 (m, 2H), 3.66 (m, 6H),
3.64 (t, 2H, J ) 5.3 Hz), 3.21 (t, 2H, J ) 5.9 Hz). Anal. Calcd
for C25H28O4 (392.49): C, 76.49; H, 7.20. Found: C, 76.41; H,
7.33.
8,8,8-Tr ip h en yl-7-oxa ct a n yl Met h a n esu lfon a t e (16),
9,9,9-Tr iph en yl-8-oxan on an yl Meth an esu lfon ate (17), 10,-
10,10-Tr ip h en yl-9-oxa d eca n yl Meth a n esu lfon a te (18), or
10,10,10-Tr iph en yl-3,6,9-tr ioxadecan yl Meth an esu lfon ate
(20). To an ice-cooled solution of MsCl (36.25 mmol) in dry
pyridine (18 mL) was added a solution of 13, 14, 15, or 19 (7.25
mmol) in dry CH2Cl2 (110 mL) dropwise under an Ar atmo-
sphere. The mixture was allowed to warm to room tempera-
ture and stirred overnight. The reaction mixture was diluted
with CH2Cl2, washed successively with 1 M HCl and brine,
and dried (Na2SO4). The solvent was evaporated, and the
residue was purified by chromatography.
16: eluent 9:1 pentane-EtOAc; yield 81%; 1H NMR (360
MHz, CDCl3) δ 7.55-7.15 (m, 15H), 4.18 (t, 2H, J ) 6.5 Hz),
3.04 (t, 2H, J ) 6.5 Hz), 2.95 (s, 3H), 1.72 (dt, 2H, J ) 7.0 Hz),
1.61 (dt, 2H, J ) 6.8 Hz), 1.45-1.25 (m, 4H); 13C NMR (75
MHz, CDCl3) δ 144.3, 128.6, 127.6, 126.8, 86.3, 69.9, 63.2, 37.2,
29.7, 29.0, 25.6, 25.2. Anal. Calcd for C26H30O4S (438.58): C,
71.20; H, 6.89; S, 7.31. Found: C, 71.43; H, 6.86; S, 7.44.
17: eluent 9:1 pentane-EtOAc; yield 78%; 1H NMR (360
MHz, CDCl3) δ 7.55-7.15 (m, 15H), 4.18 (t, 2H, J ) 6.5 Hz),
3.03 (t, 2H, J ) 6.5 Hz), 2.97 (s, 3H), 1.73 (dt, 2H, J ) 7.0 Hz),
1.52 (dt, 2H, J ) 6.5 Hz), 1.45-1.25 (m, 6H). Anal. Calcd for
C
27H32O4S (452.61): C, 71.65; H, 7.13; S, 7.08. Found: C,
71.59; H, 7.16; S, 7.05.
18: eluent 9:1 pentane-EtOAc; yield 82%; 1H NMR (360
MHz, CDCl3) δ 7.55-7.15 (m, 15H), 4.19 (t, 2H, J ) 6.6 Hz),
3.04 (t, 2H, J ) 6.5 Hz), 2.96 (s, 3H), 1.72 (dt, 2H, J ) 7.0 Hz),
1.60 (dt, 2H, J ) 6.5 Hz), 1.39-1.23 (m, 8H). Anal. Calcd for
Eth yl 2,3,4-Tr i-O-ben zyl-6-O-tr ityl-1-th io-r-D-ga la cto-
p yr a n osid e (10). Trityl chloride (4.22 g, 15.16 mmol) was
added to a solution of alcohol 36 (6.25 g, 12.63 mmol) in dry
pyridine (150 mL). The reaction mixture was stirred at 40 °C
for 8 h. The solvent was evaporated, and the resulting solid
was taken up in CHCl3, washed with a saturated NaCl
solution, dried (Na2SO4), and evaporated. Chromatography
(96:4 pentane-EtOAc) gave 10 (8.27 g, 89%): 1H NMR (360
MHz, CDCl3) δ 7.40-7.00 (m, 30H), 5.45 (d, 1H, J ) 5.5 Hz),
4.76 (d, 1H, J ) 12.0 Hz), 4.72 (d, 1H, J ) 12.0 Hz), 4.66 (d,
1H, J ) 11.5 Hz), 4.61 (d, 1H, J ) 11.5 Hz), 4.57 (d, 1H, J )
11.5 Hz), 4.36 (d, 1H, J ) 11.5 Hz), 4.18 (t, 1H, J ) 6.5 Hz),
4.15 (dd, 1H, J ) 9.9, 5.5 Hz), 3.80 (d, 1H, J ) 2.5 Hz), 3.72
(dd, 1H, J ) 9.9, 2.5 Hz), 3.34 (dd, 1H, J ) 10.9, 6.5 Hz), 3.04
(dd, 1H, J ) 10.9, 6.5 Hz), 2.51 (dq, 1H, J ) 7.4 Hz), 2.40 (dq,
1H, J ) 7.4 Hz), 1.25 (t, 3H, J ) 7.4 Hz). Anal. Calcd for
C
28H34O4S (466.64): C, 72.07; H, 7.34; S, 6.87. Found: C,
72.21; H, 7.49; S, 6.94.
1
20:29 eluent 2:1 pentane-EtOAc; yield 82%; H NMR (360
MHz, CDCl3) δ 7.50-7.18 (m, 15H), 4.34 (m, 2H), 3.78 (m, 2H),
3.66 (m, 4H), 3.64 (t, 2H, J ) 5.3 Hz), 3.21 (t, 2H, J ) 5.9 Hz),
2.94 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 144.0, 128.6, 127.7,
126.9, 86.5, 70.6, 70.6, 70.6, 69.2, 68.9, 63.2, 37.4. Anal. Calcd
for C26H30O6S (470.58): C, 66.36; H, 6.43; S, 6.81. Found: C,
66.26; H, 6.46; S, 6.99.
Meth yl 2,3-O-Isop r op ylid en e-6-O-ter t-bu tyld ip h en yl-
silyl-r-D-m a n n op yr a n osid e (22). To an ice-cooled solution
of methyl 2,3-O-isopropylidene-R-D-mannopyranoside23 21 (2.41
g, 10.33 mmol) and imidazole (3.80 g, 31.10 mmol) in dry DMF
(70 mL) was added tert-butyldiphenylsilyl chloride (4.02 mL,
15.49 mmol) under an Ar atmosphere. The mixture was
stirred for 5 h at room temperature. The reaction mixture was
washed successively with 5% HCl and a saturated NaCl
solution and dried (Na2SO4). The solvent was evaporated, and
the resulting residue was purified by chromatography (3:1
pentane-EtOAc) to afford 22 (4.87 g, 93%) as an oil: [R]D +2.5°
(c 0.9, CHCl3, lit.24); 1H NMR (360 MHz, CDCl3) δ 7.70 (m,
4H), 7.40 (m, 6H), 4.86 (s, 1H), 4.12 (dd, 1H, J ) 6.4, 5.9 Hz),
4.09 (d, 1H, J ) 5.9 Hz), 3.91 (dd, 1H, J ) 10.7, 5.0 Hz), 3.84
(dd, 1H, J ) 10.7, 4.9 Hz), 3.78 (dd, 1H, J ) 9.3, 6.4 Hz), 3.61
(ddd, 1H, J ) 9.3, 5.0, 4.9 Hz), 3.34 (s, 3H), 2.70 (bs, 1H), 1.48
(s, 3H), 1.32 (s, 3H), 1.05 (s, 9H); 13C NMR (75 MHz, CDCl3)
δ 135.6, 135.5, 133.1, 132.9, 129.7, 127.7, 127.6, 109.4, 98.1,
78.4, 75.3, 70.2, 69.6, 64.3, 54.7, 27.8, 26.73, 26.03, 19.2. Anal.
Calcd for C26H36O6Si (472.65): C, 66.07; H, 7.68. Found: C,
66.02; H, 7.34.
C
48H48O5S (736.97): C, 78.23; H, 6.57;10; S, 4.34. Found: C,
77.98; H, 6.43; S, 4.25.
8,8,8-Tr ip h en yl-7-oxa cta n ol (13), 9,9,9-Tr ip h en yl-8-ox-
a n on a n ol (14), 10,10,10-Tr ip h en yl-9-oxa d eca n ol (15), or
10,10,10-Tr ip h en yl-3,6,9-tr ioxa d eca n ol (19). To an ice-
cooled solution of 1,6-hexanediol, 1,7-heptanediol, 1,8-oc-
tanediol, or triethylene glycol (30.34 mmol) in dry pyridine (30
mL) and dry CH2Cl2 (307 mL) was added trityl chloride (36.40
mmol). The mixture was stirred overnight as it came to room
temperature. The solution was washed successively with 1
M HCl and brine and dried (Na2SO4). The solvent was
evaporated, and the resulting residue was purified by chro-
matography.
1
13:27 eluent 4:1 pentane-EtOAc; yield 52%; H NMR (360
MHz, CDCl3) δ 7.55-7.15 (m, 15H), 3.60 (t, 2H, J ) 6.0 Hz),
3.00 (t, 2H, J ) 6.5 Hz), 1.68-1.44 (m, 5H), 1.25-1.45 (m, 4H).
Anal. Calcd for C25H28O2 (360.50): C, 83.29; H, 7.83. Found:
C, 83.32; H, 7.83.
Meth yl 4-O-Ben zyl-6-O-ter t-bu tyld ip h en ylsilyl-2,3-iso-
p r op ylid en e-r-D-m a n n op yr a n osid e (23). The alcohol 22
(2.41 g, 5.12 mmol) was dissolved in dry DMF (30 mL) and
cooled to 0 °C. Then NaH (307 mg, 10.20 mmol) was added,
and the solution was stirred for 30 min, at which point benzyl
bromide (1.21 mL, 10.24 mmol) was added dropwise. The
14: eluent 4:1 pentane-EtOAc; yield 57%; 1H NMR (360
MHz, CDCl3) δ 7.55-7.15 (m, 15H), 3.52 (t, 2H, J ) 6.4 Hz),
3.05 (t, 2H, J ) 6.2 Hz), 1.63 (dt, 2H, J ) 6.3 Hz), 1.55 (dt,
2H, J ) 6.4 Hz) 1.45-1.20 (m, 7H). Anal. Calcd for C26H30O2
(374.52): C, 83.38; H, 8.07. Found: C, 83.35; H, 8.17.

Synthesis of Tethered Trisaccharides
J . Org. Chem., Vol. 63, No. 18, 1998 6295
reaction was stirred overnight as it warmed to room temper-
ature. Excess sodium hydride was quenched with methanol,
and the solution was concentrated under reduced pressure.
The resulting solid was taken up in CH2Cl2, washed with a
saturated NaCl solution, dried (Na2SO4), and evaporated.
Chromatography (95:5 pentane-EtOAc) gave 23 (2.42 g, 84%)
as a solid: [R]D +12.3° (c 1.1, CHCl3, lit.24); 1H NMR (360 MHz,
CDCl3) δ 7.72 (m, 4H), 7.36 (m, 6H), 7.25 (m, 5H), 4.93 (s, 1H),
4.85 (d, 1H, J ) 11.5 Hz), 4.55 (d, 1H, J ) 11.5 Hz), 4.31 (dd,
1H, J ) 6.3, 5.9 Hz), 4.13 (d, 1H, J ) 5.9 Hz), 3.94 (dd, 1H, J
) 10.9, 1.3 Hz), 3.85 (dd, 1H, J ) 10.9, 4.3 Hz), 3.62 (m, 2H),
3.36 (s, 3H), 1.51 (s, 3H), 1.40 (s, 3H), 1.05 (s, 9H); 13C NMR
(75 MHz, CDCl3) δ 138.3, 135.8, 135.6, 133.7, 133.3, 129.5,
128.2, 127.8, 127.60, 127.53, 127.45, 109.2, 98.1, 78.9, 75.9,
75.6, 72.8, 69.5, 63.3, 54.5, 27.9, 26.7, 26.3, 19.3. Anal. Calcd
for C33H42O6Si (562.78): C, 70.43; H, 7.52. Found: C, 70.49;
H, 7.64.
Meth yl 4-O-Ben zyl-6-O-ter t-bu tyldiph en ylsilyl-r-D-m an -
n op yr a n osid e (24). Compound 23 (1.46 g, 2.59 mmol) was
dissolved in 80% acetic acid (60 mL), and the mixture was
heated in an oil bath at 80 °C for 4 h. The solution was cooled,
the solvent was evaporated, and the residue was coevaporated
twice with toluene. Chromatography (2:1 pentane-EtOAc)
gave 24 (1.14 g, 84%) as a solid: [R]D +41.1° (c 1.0, CHCl3);
1H NMR (360 MHz, CDCl3) δ 7.75 (m, 4H), 7.35 (m, 6H), 7.22
(m, 5H), 4.74 (d, 1H, J ) 11.3 Hz), 4.72 (d, 1H, J ) 1.6 Hz),
4.63 (d, 1H, J ) 11.3 Hz), 3.94 (dd, 1H, J ) 8.3, 3.5 Hz), 3.93
(d, 1H, J ) 3.1 Hz), 3.89 (dd, 1H, J ) 3.5, 1.6 Hz), 3.72 (dd,
1H, J ) 9.6, 8.3 Hz), 3.65 (dt, 1H, J ) 9.6, 3.1 Hz), 3.35 (s,
3H), 1.10 (s, 9H); 13C NMR (75 MHz, CDCl3) δ 138.2, 135.7,
135.6, 133.6, 133.3, 129.6, 128.5, 127.8, 127.76, 127.6, 127.5,
100.3, 75.9, 74.7, 71.9, 71.8, 71.0, 63.1, 54.6, 26.8, 19.3. Anal.
Calcd for C30H38O6Si (522.71): C, 68.93; H, 7.33. Found: C,
69.01; H, 7.21.
Met h yl 3-O-Allyl-4-O-b en zyl-6-O-ter t-b u t yld ip h en yl-
silyl-r-D-m a n n op yr a n osid e (25). A solution of 24 (3.25 g,
6.22 mmol) and dibutyltin oxide (1.54 g, 6.21 mmol) in freshly
distilled methanol (40 mL) was boiled for 2.50 h. The solvent
was evaporated to dryness to give a residue, which was
dissolved in freshly distilled toluene (40 mL); then tetrabuty-
lammonium iodide (2.29 g, 6.22 mmol) and allyl bromide (30
mL) were added. The mixture was stirred for 15 h at 60 °C,
cooled to room temperature, and washed successively with 10%
Na2S2O3 and a saturated NaCl solution. The organic layer was
dried over Na2SO4 and evaporated. Chromatography of the
resulting residue (8:1 pentane-EtOAc) gave 25 (3.20 g, 92%)
as an oil: [R]D +44.8° (c 1.2, CHCl3); 1H NMR (360 MHz,
CDCl3) δ 7.72 (m, 4H), 7.36 (m, 6H), 7.25 (m, 5H), 5.92 (ddd,
1H, J ) 17.2, 10.4, 5.7 Hz), 5.33 (ddd, 1H, J ) 17.2, 3.1, 1.6
Hz), 5.18 (ddd, 1H, J ) 10.4, 3.1, 1.3 Hz), 4.80 (d, 1H, J )
10.8 Hz), 4.76 (d, 1H, J ) 1.6 Hz), 4.58 (d, 1H, J ) 10.8 Hz),
4.20 (dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.15 (dddd, 1H, J
) 12.6, 5.6, 1.6, 1.3 Hz), 4.05 (dd, 1H, J ) 2.7, 1.6 Hz), 3.88
(m, 2H), 3.78 (dd, 1H, J ) 9.0, 8.1 Hz), 3.74 (dd, 1H, J ) 8.1,
2.8 Hz), 3.65 (m, 1H), 3.37 (s, 3H), 1.05 (s, 9H); 13C NMR (75
MHz, CDCl3) δ 138.4, 135.8, 135.6, 134.6, 133.7, 133.4, 129.5,
128.3, 127.8, 127.5, 117.4, 100.1, 79.9, 75.1, 74.2, 72.3, 70.9,
68.5, 63.2, 54.5, 26.7, 19.3. Anal. Calcd for C33H42O6Si
(562.78): C, 70.43; H, 7.52. Found: C, 70.45; H, 7.71.
Meth yl 2-O-Acetyl-3-O-a llyl-4-O-ben zyl-6-O-ter t-bu tyl-
d ip h en ylsilyl-r-D-m a n n op yr a n osid e (26). To an ice-cooled
solution of 25 (3.39 g, 6.03 mmol) in dry pyridine (30 mL) was
added acetic anhydride (2 mL, 21 mmol) dropwise. The
mixture was stirred overnight at room temperature. Evapora-
tion of the solvent and chromatography of the residue (95:5
pentane-EtOAc) gave 26 (3.06 g, 84%) as an oil: [R]D +33.0°
(c 0.8, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.72 (m, 4H), 7.36
(m, 6H), 7.25 (m, 5H), 5.90 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz),
5.29 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.25 (dd, 1H, J ) 3.3, 1.7
Hz), 5.16 (ddd, 1H, J ) 10.4, 3.1, 1.3 Hz, 1H), 4.90 (d, 1H, J )
10.8 Hz), 4.69 (d, 1H, J ) 1.7 Hz), 4.58 (d, 1H, J ) 10.8 Hz),
4.16 (dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.05 (dddd, 1H, J
) 12.6, 5.6, 1.6, 1.3 Hz), 3.97 (dd, 1H, J ) 11.1, 4.1 Hz), 3.94
(dd, 1H, J ) 11.1, 9.3 Hz), 3.90 (dd, 1H, J ) 11.1, 2.1 Hz),
3.86 (dd, 1H, J ) 9.3, 3.3 Hz), 3.64 (ddd, 1H, J ) 11.1, 4.1, 2.1
Hz), 3.35 (s, 3H), 2.15 (s, 3H), 1.08 (s, 9H); 13C NMR (75 MHz,
CDCl3) δ 170.5, 138.6, 135.9, 135.6, 134.7, 133.9, 133.3, 129.6,
128.3, 127.8, 127.7, 127.5, 117.3, 98.6, 77.8, 75.3, 74.3, 72.5,
70.9, 69.3, 62.9, 54.7, 26.8, 21.1, 19.4. Anal. Calcd for
C35H44O7Si (604.81): C, 69.51; H, 7.33. Found: C, 69.41; H,
7.59.
Meth yl 2-O-Acetyl-3-O-a llyl-4-O-ben zyl-r-D-m a n n op y-
r a n osid e (27). A 1 M solution of tetrabutylammonium
fluoride in THF (27 mL, 27 mmol) was added dropwise to
compound 26 (8.18 g, 13.5 mmol) under an Ar atmosphere.
The mixture was stirred for 6 h at room temperature.
Evaporation of the solvent and chromatography of the residue
(2:1 pentane-EtOAc) gave the alcohol 27 (4.15 g, 84%) as an
1
oil: [R]D +53.3° (c 1.5, CHCl3); H NMR (360 MHz, CDCl3) δ
7.30 (m, 5H), 5.88 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.27 (ddd,
1H, J ) 17.2, 3.1, 1.6 Hz), 5.24 (dd, 1H, J ) 3.4, 1.7 Hz), 5.16
(ddd, 1H, J ) 10.4, 3.1, 1.3 Hz), 4.90 (d, 1H, J ) 10.9 Hz),
4.64 (d, 1H, J ) 1.7 H), 4.61 (d, 1H, J ) 10.9 Hz), 4.14 (dddd,
1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.02 (dddd, 1H, J ) 12.6, 5.6,
1.6, 1.3 Hz), 3.84 (dd, 1H, J ) 9.3, 3.4 Hz, 1H), 3.80 (m, 2H),
3.72 (dd, 1H, J ) 9.7, 9.3 Hz), 3.62 (ddd, 1H, J ) 9.7, 3.8, 3.1
Hz), 3.32 (s, 3H), 2.12 (s, 3H); 13C NMR (75 MHz, CDCl3) δ
170.2, 138.3, 134.5, 128.3, 127.9, 127.7, 117.1, 98.7, 77.5, 75.1,
74.1, 71.5, 70.6, 68.8, 62.0, 54.8, 20.9. Anal. Calcd for
C19H26O7 (366.41): C, 62.28; H, 7.15. Found: C, 62.08; H, 7.10.
Meth yl 2-O-Acetyl-3-O-a llyl-4-O-ben zyl-6-O-m eth a n e-
su lfon yl-r-D-m a n n op yr a n osid e (28). To an ice-cooled solu-
tion of methanesulfonyl chloride (5.43 g, 70.42 mmol) in dry
pyridine (30 mL) was added a solution of 27 (5.15 g, 14.08
mmol) dropwise under an Ar atmosphere. The solution was
stirred overnight as it came to room temperature. The reaction
mixture was diluted with CH2Cl2 and then washed with 1 M
HCl and a saturated NaCl solution, dried over Na2SO4, and
evaporated. Chromatography (3:1 pentane-EtOAc) afforded
28 (5.50 g, 88%) as an oil: [R]D +59.2° (c 0.6, CHCl3); 1H NMR
(360 MHz, CDCl3) δ 7.30 (m, 5H), 5.87 (ddd, 1H, J ) 17.2,
10.4, 5.7 H), 5.28 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.24 (dd,
1H, J ) 3.3, 1.7 Hz), 5.16 (ddd, 1H, J ) 10.4, 3.1, 1.3 Hz),
4.93 (d, 1H, J ) 10.8 Hz), 4.65 (d, 1H, J ) 1.7 Hz), 4.61 (d,
1H, J ) 10.8 Hz), 4.45 (d, 2H, J ) 3.3 Hz), 4.14 (dddd, 1H, J
) 12.6, 5.6, 1.6, 1.3 Hz), 4.01 (dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3
Hz), 3.85 (dd, 1H, J ) 9.1, 3.3 Hz), 3.81 (ddd, 1H, J ) 9.9, 3.3
Hz), 3.70 (dd, 1H, J ) 9.9, 9.1 Hz), 3.35 (s, 3H), 3.05 (s, 3H),
2.12 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 169.9, 137.8, 134.2,
128.3, 127.9, 127.7, 117.2, 98.7, 77.4, 75.1, 73.3, 70.5, 69.6, 68.9,
68.4, 55.1, 37.5, 20.8. Anal. Calcd for C20H28O9S (444.50): C,
54.04; H, 6.35, S, 7.21. Found: C, 53.89; H, 6.39; S, 7.46.
Meth yl 4-O-Ben zyl-2,3-isop r op ylid en e-r-D-m a n n op y-
r a n osid e (29). A 1 M solution of tetrabutylammonium
fluoride in THF (48.7 mL, 48.70 mmol) was added dropwise
to compound 23 (18.25 g, 32.47 mmol) under an Ar atmo-
sphere. The mixture was stirred for 9 h at room temperature.
The solvent was evaporated, and the resulting residue was
purified by chromatography (4:1 pentane-EtOAc) to provide
29 (9.03 g, 86%) as an oil: [R]D +63.6° (c 1.2, CHCl3); 1H NMR
(360 MHz, CDCl3) δ 7.35-7.25 (m, 5H), 4.89 (s, 1H), 4.87 (d,
1H, J ) 11.6 Hz), 4.61 (d, 1H, J ) 11.6 Hz), 4.29 (dd, 1H, J )
6.7, 5.9 Hz), 4.11 (d, 1H, J ) 5.9 Hz), 3.83 (ddd, 1H, J ) 11.7,
5.7, 3.2 Hz), 3.71 (ddd, 1H, J ) 11.7, 7.6, 4.3 Hz), 3.60 (ddd,
1H, J ) 10.0, 4.3, 3.2 Hz), 3.51 (dd, 1H, J ) 10.0, 6.7 Hz),
3.35 (s, 3H), 2.05 (dd, 1H, J ) 7.6, 5.7 Hz), 1.49 (s, 3H), 1.35
(s, 3H); 13C NMR (75 MHz, CDCl3) δ 138.0, 128.2, 127.9, 127.6,
109.2, 98.1, 78.5, 75.6, 68.4, 62.3, 54.7, 27.8, 26.2. Anal. Calcd
for C17H24O6 (324.37): C, 62.95; H, 7.46. Found: C, 62.66; H,
7.78.
Meth yl 4-O-Ben zyl-2,3-isopr opyliden e-6-O-(8′-tr ityloxy-
octyl)-r-D-m a n n op yr a n osid e (30). To a solution of alcohol
29 (1.21 g, 3.76 mmol) in dry THF (50 mL) was added NaH
(338 mg, 11.28 mmol) under Ar. After being stirred for 1 h at
50 °C, a solution of 18 (2.36 g, 5.07 mmol) in dry THF (8 mL)
was added dropwise. Then, the reaction mixture was stirred
at 65 °C for 19 h and cooled to room temperature and the
excess of NaH decomposed with MeOH. The solvent was
evaporated, and the resulting residue dissolved in CH2Cl2,
washed with a saturated NaCl solution, and dried (Na2SO4).

6296 J . Org. Chem., Vol. 63, No. 18, 1998
Alibe´s and Bundle
Evaporation of the solvent and chromatography (0 f 10%
EtOAc in pentane) gave 30 (2.19 g, 84%) as an oil: [R]D + 23.0°
(c 1.4, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.48-7.15 (m,
20H), 4.91 (s, 1H), 4.86 (d, 1H, J ) 11.6 Hz), 4.57 (d, 1H, J )
11.6 Hz), 4.28 (dd, 1H, J ) 6.4, 6.4 Hz), 4.09 (d, 1H, J ) 6.4
Hz), 3.70-3.64 (m, 2H), 3.58 (ddd, 1H, J ) 10.5, 5.2 Hz), 3.52
(dd, 1H, J ) 10.3, 6.4 Hz), 3.48 (dt, 1H, J ) 9.2, 6.6 Hz), 3.39
(dt, 1H, J ) 9.2, 6.8 Hz), 3.35 (s, 3H), 3.01 (t, 2H, J ) 6.6 Hz),
1.55 (m, 4H), 1.49 (s, 3H), 1.35 (s, 3H), 1.25 (m, 8H). Anal.
Calcd for C44H54O7 (694.91): C, 76.05; H, 7.83. Found: C,
75.90; H, 7.94.
Meth yl 4-O-Ben zyl-6-O-(8′-h ydr oxyoctyl)-r-D-m an n opy-
r a n osid e (31). Trityl compound 30 (1.69 g, 2.44 mmol) was
dissolved in 9:1 MeOH:EtOAc (30 mL), and p-toluensulfonic
acid was added until the pH was 4. The reaction mixture was
stirred for 48 h, triethylamine (500 µL) was added, and the
solvents were evaporated. The residue was purified by chro-
matography (EtOAc) to afford 31 (800 mg, 80%) as an oil: [R]D
+59.6° (c 1.7, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.35-7.25
(m, 5H), 4.78 (d, 1H, J ) 11.4 Hz), 4.71 (d, 1H, J ) 1.4 Hz),
4.67 (d, 1H, J ) 11.4 Hz), 3.88 (dd, 1H, J ) 8.1, 3.5 Hz), 3.85
(d, 1H, J ) 3.5, 1.4 Hz), 3.72-3.62 (m, 4H), 3.59 (t, 2H, J )
6.6 Hz), 3.53 (dt, 1H, J ) 9.3, 6.5 Hz), 3.40 (dt, 1H, J ) 9.3,
6.8 Hz), 3.33 (s, 3H), 2.55 (sb, 3H), 1.65-1.55 (m, 4H), 1.25
(m, 8H); 13C NMR (75 MHz, CDCl3) δ 138.4, 128.3, 127.7, 127.5,
100.7, 75.6, 74.5, 71.8, 71.6, 70.9, 70.3, 69.4, 62.5, 54.7, 32.3,
5.34 mmol) was dissolved in dry DMF (40 mL) and cooled to 0
°C. Then NaH (1.025 g, 34.19 mmol) was added and the
solution stirred for 30 min, at which point benzyl bromide (4
mL, 34.19 mmol) was added dropwise. The reaction was
stirred overnight as the solution warmed to room temperature.
Excess sodium hydride was quenched with methanol, and the
solution was concentrated under reduced pressure. The
resulting solid was taken up in CHCl3, washed with
a
saturated NaCl solution, dried (Na2SO4), and evaporated.
Chromatography (96:4 pentane-EtOAc) gave 35 (2.84 g, 74%)
as a solid: [R]D +95.5° (c 1.7, CHCl3); 1H NMR (360 MHz,
CDCl3) δ 7.60 (m, 4H), 7.40-7.18 (m, 21H), 5.48 (d, 1H, J )
5.5 Hz), 4.94 (d, 1H, J ) 11.4 Hz), 4.87 (d, 1H, J ) 11.8 Hz),
4.75 (d, 1H, J ) 12.5 Hz), 4.71 (d, 2H, J ) 12.5 Hz), 4.67 (d,
1H, J ) 11.8 Hz), 4.59 (d, 1H, J ) 11.4 Hz), 4.26 (dd, 1H, J )
9.9, 5.5 Hz), 4.15 (t 1H, J ) 6.5 Hz), 3.93 (d, 1H, J ) 2.9 Hz),
3.80 (dd, 1H, J ) 9.9, 2.9 Hz), 3.69 (d, 2H, J ) 6.5 Hz), 2.51
(dq, 1H, J ) 7.4 Hz), 2.40 (dq, 1H, J ) 7.4 Hz), 1.19 (t, 3H, J
) 7.4 Hz), 1.05 (s, 9H). Anal. Calcd for C45H52O5Si (733.05):
C, 73.73; H, 7.15; S, 4.37. Found: C, 73.87; H, 7.27; S, 4.48.
Eth yl 2,3,4-Tr i-O-ben zyl-1-th io-r-D-ga la ctop yr a n osid e
(36). A 1 M solution of tetrabutylammonium fluoride in THF
(5.5 mL, 5.5 mmol) was added dropwise to compound 35 (2.03
g, 2.77 mmol) under an Ar atmosphere, and the mixture was
stirred for 6 h at room temperature. Evaporation of the solvent
and chromatography (2:1 pentane-EtOAc) of the residue
afforded the alcohol 36 (1.30 g, 95%) as a white solid: [R]D
29.3, 29.2, 29.1, 25.8, 25.5. Anal. Calcd for
(412.52): C, 64.05; H, 8.80. Found: C, 63.64; 8.92.
C22H36O7
1
+110° (c 1.0, CHCl3); H NMR (360 MHz, CDCl3) δ 7.30 (m,
Meth yl 3-O-Allyl-4-O-ben zyl-6-O-(8′-h yd r oxyoctyl)-r-D-
m a n n op yr a n osid e (32). A solution of 31 (794 mg, 1.92
mmol) and dibutyltin oxide (526 mg, 2.11 mmol) in freshly
distilled methanol (15 mL) was boiled for 2.30 h. The solvent
was evaporated to dryness to give a residue, which was
dissolved in freshly distilled toluene (15 mL); then tetrabuty-
lammonium iodide (711 mg, 1.92 mmol) and allyl bromide (1.46
mL, 19.2 mmol) were added. The mixture was stirred for 15
h at 65 °C, cooled to room temperature, and washed succes-
sively with 10% Na2S2O3 and a saturated NaCl solution. The
organic layer was dried over Na2SO4 and evaporated. Chro-
matography of the resulting residue (1:1 EtOAc-pentane) gave
32 (610 mg, 70%) as an oil: [R]D +62.5° (c 2.2, CHCl3); 1H NMR
(360 MHz, CDCl3) δ 7.35-7.25 (m, 5H), 5.92 (ddd, 1H, J )
17.2, 10.4, 5.7 Hz), 5.33 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.18
(ddd, 1H, J ) 10.4, 3.1, 1.3 Hz), 4.84 (d, 1H, J ) 11.0 Hz),
4.75 (d, 1H, J ) 1.7 Hz), 4.58 (d, 1H, J ) 11.0 Hz), 4.17 (dddd,
1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.11 (dddd, 1H, J ) 12.6, 5.6,
1.6, 1.3 Hz), 3.96 (ddd, 1H, J ) 3.2, 3.0, 1.7 Hz), 3.77 (dd, 1H,
J ) 8.9, 8.8 Hz), 3.71 (dd, 1H, J ) 8.9, 3.2 Hz), 3.68-3.60 (m,
3H), 3.58 (t, 2H, J ) 6.6 Hz), 3.51 (dt, 1H, J ) 9.3, 6.5 Hz),
3.39 (dt, 1H, J ) 9.3, 6.7), 3.33 (s, 3H), 2.51 (d, 1H, J ) 3.0
Hz), 1.65-1.55 (m, 4H), 1.25 (m, 8H); 13C NMR (75 MHz,
CDCl3) δ 138.4, 134.5, 128.2, 127.7, 127.5, 117.1, 100.3, 79.6,
74.9, 74.1, 71.6, 70.7, 69.5, 68.3, 62.6, 54.6, 32.5, 29.4, 29.2,
29.1, 25.9, 25.5; HR FABMS (M+ + Na) 475.2672, found
475.2670.
Eth yl 6-O-ter t-Bu tyld ip h en ylsilyl-1-th io-r-D-ga la cto-
p yr a n osid e (34). To an ice-cooled solution of 3326 (1.43 g,
6.40 mmol) and imidazole (871 mg, 12.08 mmol) in dry DMF
(60 mL) was added tert-butyldiphenylsilyl chloride (1.8 mL,
7.04 mmol). The stirred mixture was allowed to reach room
temperature overnight under an Ar atmosphere. The solvent
was evaporated, and the resulting residue was purified by
chromatography (EtOAc) to provide 34 (2.58 g, 88%) as a white
foam: [R]D +135.2° (c 0.8, CHCl3); 1H NMR (360 MHz, CDCl3)
δ 7.65 (m, 4H), 7.40 (m, 6H), 5.42 (d, 1H, J ) 5.5 H), 4.17 (dd,
1H, J ) 5.5, 5.5 Hz), 4.12 (dd, 1H, J ) 9.9, 5.5 Hz), 4.11 (d,
1H, J ) 3.3 Hz), 3.91 (dd, 1H, J ) 10.7, 5.5 Hz), 3.70 (dd, 1H,
J ) 10.7, 5.2 Hz), 3.54 (dd, 1H, J ) 9.9, 3.3 Hz), 2.62 (dq, 1H,
J ) 7.4 Hz), 2.55 (dq, 1H, J ) 7.4 Hz), 1.26 (t, 3H, J ) 7.4
Hz), 1.05 (s, 9H); 13C NMR (75 MHz, CDCl3) δ 135.62, 135.56,
133.2, 133.05, 129.8, 127.7, 85.8, 71.7, 70.9, 69.8, 68.7, 63.7,
26.8, 24.5, 19.1, 14.9. Anal. Calcd for C24H34O5SSi (462.67):
C, 62.30; H, 7.41; S, 6.93. Found: C, 62.31; H, 7.55; S, 6.54.
Eth yl 2,3,4-Tr i-O-ben zyl-6-O-ter t-bu tyld ip h en ylsilyl-1-
th io-r-D-ga la ctop yr a n osid e (35). The alcohol 34 (2.47 g,
15H), 5.49 (d, 1H, J ) 5.5 Hz), 4.96 (d, 1H, J ) 11.6 Hz), 4.86
(d, 1H, J ) 11.6 Hz), 4.74 (d, 1H, J ) 11.6 Hz), 4.70 (d, 1H, J
) 11.6 Hz), 4.66 (d, 1H, J ) 11.6 Hz), 4.62 (d, 1H, J ) 11.6
Hz), 4.29 (dd, 1H, J ) 9.8, 5.5 Hz), 4.10 (ddd, 1H, J ) 6.4, 5.2,
1.2 Hz), 3.86 (dd, 1H, J ) 2.8, 1.2 Hz), 3.78 (dd, 1H, J ) 9.9,
2.9 Hz), 3.71 (dd, 1H, J ) 11.5, 6.4 Hz), 3.50 (dd, 1H, J ) 11.5,
5.2 Hz), 2.70 (dq, 1H, J ) 7.4 Hz), 2.62 (dq, 1H, J ) 7.4 Hz),
1.24 (t, 3H, J ) 7.4 Hz); 13C NMR (75 MHz, CDCl3) 138.6,
138.1, 128.4, 128.34, 128.28, 127.8, 127.5, 127.45, 83.2, 79.4,
76.1, 75.0, 74.4, 73.5, 72.4, 70.61, 62.2, 23.4, 14.5. Anal. Calcd
for C29H34O5S (494.64): C, 70.42; H, 6.93; S, 6.48. Found: C,
70.24; H, 6.97; S, 6.68.
Meth yl 3-O-Allyl-2-O-[2′,3′,4′-tr i-O-ben zyl-6′-O-(6′′-tr i-
tyloxyh exyl)-r-D-galactopyr an osyl]-4-O-ben zyl-6-O-m eth -
a n esu lfon yl-r-D-m a n n op yr a n osid e (37). The alcohol 5 (387
mg, 0.96 mmol) and the thioglycoside 6 (1.16 g, 1.39 mmol)
were dried in vacuo with powdered 4 Å molecular sieves over
P2O5 overnight. The mixture was suspended in CH2Cl2 (15
mL) under an Ar atmosphere and stirred for 2 h at room
temperature. N-Iodosuccinimide (476 mg, 2.11 mmol) was
added, and the suspension was stirred for 10 min before rapid,
dropwise addition of a saturated solution of triflic acid in ca.
0.15 M CH2Cl2 (770 µL, 0.11 mmol). The reaction was
quenched with triethylamine, diluted with CH2Cl2, and filtered
through Celite. The filtrate was washed successively with 10%
Na2S2O3 and a saturated NaCl solution. After evaporation of
the solvent the residue was chromatographed (0 f 25% ethyl
acetate in pentane) to provide 37 (1.26 g, 77%) as an oil: [R]D
+62.5° (c 1.3, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.5-7.15
(m, 35H), 5.89 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), (d, 1H, J )
3.8 Hz), 5.28 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.16 (ddd, 1H, J
) 10.4, 3.1, 1.3 Hz), 4.97 (d, 2H, J ) 11.9 Hz), 4.83 (d, 1H, J
) 12.2 Hz), 4.76 (d, 1H, J ) 12.2 Hz), 4.71 (d, 1H, J ) 11.6
Hz), 4.67 (s, 1H), 4.66 (d, 1H, J ) 11.4 Hz), 4.61 (d, 1H, J )
11.5 Hz), 4.51 (dd, 1H, J ) 11.7, 0.5 Hz), 4.39 (dd, 1H, J )
11.7, 4.0 Hz), 4.31 (d, 1H, J ) 10.9 Hz), 4.16 (dddd, 1H, J )
12.6, 5.6, 1.6, 1.3 Hz), 4.12 (m, 2H), 4.08 (dd, 1H, J ) 9.9, 3.8
Hz), 3.94 (d, 1H, J ) 2.5 Hz), 3.90 (dd, 1H, J ) 9.8, 9.7 Hz),
3.85 (dd, 1H, J ) 6.2, 5.5 Hz), 3.79 (dd, 2H, J ) 9.9, 2.5 Hz
and J ) 9.8, 2.5 Hz), 3.69 (ddd, 1H, J ) 9.7, 4.0, 0.5 Hz), 3.49
(dd, 1H, J ) 9.7, 6.2 Hz), 3.41 (m, 2H), 3.30 (s, 3H), 3.28 (dt,
1H, J ) 9.2, 2.7 Hz), 3.05 (t, 2H, J ) 6.6 Hz), 2.95 (s, 3H),
1.70-1.20 (m, 8H); 13C NMR (75 MHz, CDCl3) δ 144.40, 138.8,
138.7, 138.5, 138.2, 134.4, 128.6, 128.4, 128.3, 128.2, 127.7,
127.6, 127.6, 127.3, 127.1, 126.8, 117.1, 100.2, 97.3, 86.2, 80.0,
78.0, 76.3, 74.8, 74.8, 74.7, 73.8, 72.6, 71.6, 71.5, 71.3, 71.2,
70.5, 69.9, 69.8, 69.3, 63.5, 54.9, 37.9, 29.9, 29.6, 26.1, 25.9.

Synthesis of Tethered Trisaccharides
J . Org. Chem., Vol. 63, No. 18, 1998 6297
Anal. Calcd for C70H80O14S (1177.46): C, 71.41; H, 6.85; S,
2.72. Found: C, 71.47; H, 6.78; S, 2.78.
4.84 (d, 1H, J ) 11.9 Hz), 4.80 (d, 1H, J ) 1.8 Hz), 4.73 (d,
1H, J ) 3.7 Hz), 4.73 (bs, 2H), 4.65 (d, 1H, J ) 11.8 Hz), 4.57
(d, 1H, J ) 11.3 Hz), 4.11 (dd, 1H, J ) 8.4, 5.3 Hz), 3.99 (bs,
1H), 3.98 (dd, 1H, J ) 9.9, 3.7 Hz), 3.95 (dd, 1H, J ) 9.0, 3.5
Hz), 3.83 (dd, 1H, J ) 9.9, 2.9 Hz), 3.64 (dd, 1H, J ) 10.1, 1.9
Hz), 3.62 (m, 1H), 3.60 (dd, 1H, J ) 10.1, 8.4 Hz), 3.57 (ddd,
1H, J ) 9.9, 5.2, 1.9 Hz), 3.50-3.36 (m, 6H), 3.29 (s, 3H), 3.23
(dd, 1H, J ) 10.1, 5.3 Hz), 1.20-1.69 (m, 8H). Anal. Calcd
for C47H58O11: C, 70.66; H, 7.32. Found: C,70.47; H, 7.27.
Meth yl 2-O-(2′′,3′′,4′′-Tr i-O-ben zyl-r-D-ga la ctop yr a n o-
syl)-3-O-(2′,4′-d i-O-ben zyl-3′,6′-d id eoxy-r-D-xylo-h exop y-
r a n osyl)-4-O-ben zyl-6,6′-d i-O-(h exa n e-1,6-d iyl)-r-D-m a n -
n op yr a n osid e (49). The disaccharide alcohol 46 (135 mg,
0.17 mmol) and the 3,6-dideoxyhexose thioglycoside 11 (288
mg, 0.77 mmol) were dried in vacuo with powdered and freshly
activated 4 Å molecular sieves over P2O5 overnight. The
mixture was suspended in dry CH2Cl2 (5 mL), cooled to -45
°C, and stirred for 20 min. N-Iodosuccinimide (185 mg, 0.82
mmol) and a solution of silver triflate (21 mg, 0.08 mmol) in
dry toluene (200 µL) was added rapidly, dropwise, and after
30 min the reaction was quenched with triethylamine. The
reaction was then diluted with CH2Cl2 and filtered, and the
filtrate was washed successively with Na2S2O3 and a saturated
NaCl solution and dried (Na2SO4). After evaporation of
solvent, the residue was purified by chromatography (84:16
pentane-EtOAc) to afford 49 (112 mg, 60%) as an oil: [R]D
+77.7° (c 1.7, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.50-7.15
(m, 30H), 5.09 (d, 1H, J ) 11.6 Hz), 5.04 (d, 1H, J ) 3.3 Hz),
4.98 (d, 1H, J ) 1.8 Hz), 4.94 (d, 1H, J ) 2.7 Hz), 4.92 (d, 1H,
J ) 12.5 Hz), 4.89 (d, 1H, J ) 11.6 Hz), 4.75 (bs, 2H), 4.64 (d,
1H, J ) 10.8 Hz), 4.62 (d, 1H, J ) 11.4 Hz), 4.58 (d, 1H, J )
11.8 Hz), 4.39 (d, 1H, J ) 12.5 Hz), 4.32 (d, 1H, J ) 12.5 Hz),
4.30 (dd, 1H, J ) 9.3, 5.0 Hz), 4.22 (d, 1H, J ) 12.0 Hz), 4.10
(dd, 1H, J ) 9.5, 3.2 Hz), 4.09-4.05 (m, 4H), 4.04 (d, 1H, J )
12.06 Hz), 3.83 (dd, 1H, J ) 3.2, 1.8 Hz), 3.76 (dd, 1H, J )
9.9, 9.5 Hz), 3.69 (ddd, 1H, J ) 9.9, 6.1, 1.7 Hz), 3.67 (m, 1H),
3.63 (dd, 1H, J ) 9.9, 1.7 Hz), 3.59 (dd, 1H, J ) 9.3, 9.1 Hz),
3.50-3.35 (m, 4H), 3.32 (s, 3H), 3.31 (dd, 1H, J ) 9.9, 6.1 Hz),
3.24 (dd, 1H, J ) 9.1, 5.0 Hz), 2.36 (bs, 1H), 1.75 (ddd, 12.9,
11.9, 2.4 Hz), 1.70 (ddd, 1H, J ) 12.9, 3.5, 3.5 Hz), 1.25-1.62
Meth yl 3-O-Allyl-2-O-[2′,3′,4′-tr i-O-ben zyl-6′-O-(6′′-h y-
d r oxyh exyl)-r-D-ga la ctop yr a n osyl]-4-O-ben zyl-6-O-m eth -
a n esu lfon yl-r-D-m a n n op yr a n osid e (40). Disaccharide 37
(584 mg, 0.49 mmol) was dissolved in 9:1 MeOH:EtOAc (10
mL), and a catalytic amount of p-toluensulfonic acid was
added. The reaction mixture was stirred for 6 h. Triethy-
lamine (100 µL) was added, solvents were evaporated, and the
residue was purified by chromatography (6:4 pentane-EtOAc)
to provide 40 (404 mg, 87%) as an oil: [R]D +78.8° (c 1.8,
CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.50-7.15 (m, 20H), 5.89
(ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.50 (d, 1H, J ) 3.5 Hz),
5.28 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.16 (ddd, 1H, J ) 10.4,
3.1, 1.3 Hz), 4.98 (d, 1H, J ) 11.5 Hz), 4.97 (d, 1H, J ) 11.6
Hz), 4.82 (d, 1H, J ) 12.2 Hz), 4.76 (d, 1H, J ) 12.2 Hz), 4.70
(d, 1H, J ) 11.5 Hz), 4.68 (s, 1H), 4.66 (d, 1H, J ) 11.4 Hz),
4.62 (d, 1H, J ) 11.8 Hz), 4.50 (d, 1H, J ) 11.7 Hz), 4.38 (dd,
1H, J ) 11.7, 2.5 Hz), 4.30 (d, 1H, J ) 10.9 Hz), 4.16 (m, 2H),
4.12 (m, 1H), 4.08 (dd, 1H, J ) 9.9, 3.5 Hz), 3.92 (bs, 1H), 3.88
(dd, 1H, J ) 9.9, 9.4), 3.85 (dd, 1H, J ) 6.4, 5.7 Hz), 3.78 (m,
2H), 3.67 (dd, 1H, J ) 9.4, 2.5 Hz), 3.61 (t, 2H, J ) 6.5 Hz),
3.48 (dd, 1H, J ) 9.5, 6.4 Hz), 3.41 (m, 2H), 3.32 (m, 1H), 3.31
(s, 3H), 2.92 (s, 3H), 1.70-1.20 (m, 8H); 13C NMR (75 MHz,
CDCl3) δ 138.7, 138.6, 138.4, 138.1, 134.4, 128.3, 128.2, 128.1,
128.1, 127.6, 127.5, 127.5, 127.5, 127.2, 127.1, 117.1, 100.1,
97.3, 79.8, 77.9, 76.2, 74.8, 74.8, 74.6, 73.7, 72.6, 71.5, 71.3,
71.3, 71.2, 70.4, 69.8, 69.8, 69.3, 62.5, 54.8, 37.8, 32.5, 29.5,
25.8, 25.4. Anal. Calcd for C51H66O14S (935.14): C, 65.50, H,
7.11; S, 3.43. Found: C, 65.60; H, 7.17; S, 3.49.
Meth yl 2-O-(3′-O-Allyl-4′-O-ben zyl-r-D-ga la ctop yr a n o-
syl)-2,3,4-tr i-O-ben zyl-6,6′-di-O-(h exan e-1,6-diyl)-r-D-m an -
n op yr a n osid e (43). A solution of disaccharide 40 (350 mg,
0.37 mmol) in dry THF (20 mL) was slowly added to a boiling
mixture of NaH (116 mg, 4.86 mmol) and Cs2CO3 (171 mg,
0.48 mmol) in dry THF (25 mL) over a 2 h period, and the
reaction mixture was then refluxed for 24 h. After an excess
of NaH has been decomposed with MeOH, the solvent was
evaporated under reduced pressure and the resulting residue
taken up in CH2Cl2 and washed with a saturated NaCl
solution. Evaporation of the solvent and chromatography (85:
15 pentane-EtOAc) gave 43 (120 mg, 38%) as an oil: [R]D
+42.3° (c 0.6, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.50-7.15
(m, 20H), 5.83 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.21 (ddd,
1H, J ) 17.2, 3.1, 1.6 Hz), 5.04 (ddd, 1H, J ) 10.4, 3.1, 1.3
Hz), 4.98 (d, 1H, J ) 2.0 Hz), 4.93 (d, 1H, J ) 11.5 Hz), 4.91
(d, 1H, J ) 11.0 Hz), 4.88 (d, 1H, J ) 3.0 Hz), 4.81 (d, 1H, J
) 11.5 Hz), 4.78 (d, 1H, J ) 11.5 Hz), 4.76 (d, 1H, J ) 11.5
Hz), 4.67 (d, 1H, J ) 12.5 Hz), 4.64 (d, 1H, J ) 12.0 Hz), 4.55
(d, 1H, J ) 11.0 Hz), 4.20 (dd, 1H, J ) 8.5, 5.3 Hz), 4.14 (dddd,
1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.05-4.00 (m, 3H), 3.99 (dd,
1H, J ) 10.1, 2.7 Hz), 3.84 (dd, 1H, J ) 9.1, 3.2 Hz), 3.79 (dd,
1H, J ) 3.2, 2.0 Hz), 3.72 (dd, 1H, J ) 9.8, 9.1 Hz), 3.68 (dd,
1H, J ) 9.9, 1.7 Hz), 3.64 (ddd, 1H, J ) 9.8, 6.1, 1.7 Hz), 3.54
(dd, 1H, J ) 9.3, 8.5 Hz), 3.49 (ddd, 1H, J ) 10.2, 6.1, 4.1 Hz),
3.43 (m, 2H), 3.40 (m, 1H), 3.39 (dd, 1H, J ) 9.9, 6.1 Hz), 3.29
(s, 3H), 3.05 (dd, 1H, J ) 9.3, 5.3 Hz), 1.69-1.20 (m, 8H);
FABMS calcd for [C50H62O11Na] 861.4, found 861.2. Anal.
Calcd for C50H62O11: C, 71.58; H, 7.45. Found: C,71.38; H,
7.34.
(m, 8H), 1.36 (d, 3H, J ) 6.6 Hz). Anal. Calcd for C67H80O14
:
C, 72.54; H, 7.27. Found: C,72.63; H, 7.24.
Meth yl 2-O-(r-D-Ga la ctop yr a n osyl)-3-O-(3′,6′-d id eoxy-
r-D-xylo-h exop yr a n osyl)-6,6′′-d i-O-(h exa n e-1,6-d iyl)-r-D-
m a n n op yr a n osid e (2). A stirred solution of 49 (87 mg, 0.08
mmol) in acetic acid (9 mL) was hydrogenated over 10% Pd/C
(101 mg) under a flow of H2 overnight. The catalyst was
removed by filtration, and the solvent was evaporated. Chro-
matography (85:15 CH2Cl2-MeOH) on Iatrobeads afforded 2
(40 mg, 90%) as a white solid: [R]D +102.8° (c 1.5, H2O);1H
NMR (500 MHz, D2O) δ 5.10 (d, 1H, J 1,2 ) 1.9 Hz, H1), 5.05
(d, 1H, J 1,2 ) 3.8 Hz, H1′), 5.01 (d, 1H, J 1,2 ) 4.0 Hz, H1′′),
4.30 (m, 1H, H5′′), 4.02 (m, 1H, J 2,3ax ) 8.6, J 2,3eq ) 8.6 Hz,
H2′), 4.10 (m, H-5′), 4.00 (dd, 1H, J 4,5 ) 0.9, Hz, H4′′), 3.96
(dd 1H, J 3,4 ) 9.7 Hz, H3), 3.92 (m, J 5,6a ) 1.7 Hz, H6a), 3.91
(ddd, 1H, J 3,4 ) 3.4, Hz, H3′′), 3.88 (dd, 1H, J 2,3 ) 3.1 Hz, H2),
3.85 (m, J 4,5 ) 1.2 Hz, H-4′), 3.82 (dd 1H, J 4,5 ) 9.7 Hz, H4),
3.75 (dd, 1H, J 2,3 ) 10.4, Hz, H2′′), 3.71 (m, 1H, OCH2), 3.70
(m, H5), 3.69 (dd, 1H, J 5,6a ) 6.6, Hz, H6a′′), 3.64 (m, 1H,
OCH2), 3.59 (m, 1H, OCH2), 3.59 (m, J 5,6b ) 7.5 Hz, H6b), 3.55
(m, 1H, OCH2), 3.52 (dd, 1H, J 5,6a ) 6.6, Hz, H6b′′), 1.97 (m,
2H, J 3eq,4 ) J 3ax,4 ) 3.2 Hz, H-3′), 1.7-1.3 (m, 8H, OCH2(CH2)4-
CH2O), 1.17 (d, 3H, J 5,6 ) 6.7 Hz, H-6′). 13C NMR (125 MHz,
Meth yl 2-O-(2′,3′,4′-Tr i-O-ben zyl-r-D-galactopyr an osyl)-
4-O-ben zyl-6,6′-d i-O-(h exa n e-1,6-d iyl)-r-D-m a n n op yr a n o-
sid e (46). A solution of disaccharide 43 (205 mg, 0.24 mmol)
in dry DMSO (2 mL) was heated at 80 °C, and KOtBu (109
mg, 0.97 mmol) was added. After 2 h, the isomerization was
complete. The mixture was cooled to room temperature,
diluted with CH2Cl2, washed with water, and dried (Na2SO4).
The solvent was evaporated and the residue redissolved in 9:1
acetone-water (15 mL). Mercuric oxide (25 mg, 0.11 mmol)
and mercuric chloride (1.46 g, 5.38 mmol) were added, and
the solution was stirred for 30 min. The solvent was evapo-
rated, and the residue was purified by chromatography (80:
20 pentane-EtOAc) to afford 46 (167 mg, 86%) as an oil: [R]D
+55.5° (c 1.1, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.50-7.15
(m, 20H), 4.93 (d, 1H, J ) 11.5 Hz), 4.91 (d, 1H, J ) 11.1 Hz),
1
1
D2O) δ 102.7 (1C, J C,H ) 169.5 Hz, C1′′), 101.5 (1C, J C,H
)
1
170.6 Hz, C1′), 99.7 (1C, J C,H ) 173.3 Hz, C1), 81.2 (1C, C2),
78.5 (1C, C3), 72.1 (1C, C5), 71.3 (1C, OCH2), 71.2 (1C, OCH2),
70.9 (1C, C6), 70.4 (1C, C3′′), 69.8 (1C, C4′′), 69.7 (1C, C5′′),
69.5 (1C, C2′′), 69.1 (1C, C4′), 68.8 (1C, C6′′), 67.9 (1C, C4),
67.4 (1C, C5′), 64.2 (1C, C2′), 33.7 (1C, C3′), 28.5 (1C, -CH2-),
28.2 (1C, -CH2-), 24.7 (2C, -CH2-), 16.2 (1C, C6′); ES HRMS
calcd for [C25H44O14Na] 591.2629, found 591.2626.
Meth yl 2-O-[2′,3′,4′-Tr i-O-ben zyl-6′-O-(7′′-tr ityloxyh ep -
tyl)-r-D-galactopyr an osyl]-3-O-allyl-4-O-ben zyl-6-O-m eth -
a n esu lfon yl-r-D-m a n n op yr a n osid e (38). The alcohol 5 (476
mg, 1.18 mmol) and the thioglycoside 7 (1.31 g, 1.55 mmol)

6298 J . Org. Chem., Vol. 63, No. 18, 1998
Alibe´s and Bundle
were dried in vacuo with powdered 4 Å molecular sieves over
P2O5 overnight. The mixture was suspended in CH2Cl2 (20
mL) under an Ar atmosphere and stirred for 2 h at room
temperature. N-Iodosuccinimide (586 mg, 2.60 mmol) was
added, and the suspension was stirred for 10 min before rapid,
dropwise addition of a saturated solution of triflic acid in ca.
0.15 M CH2Cl2 (933 µL, 0.14 mmol). The reaction was
quenched with triethylamine, diluted with CH2Cl2, and filtered
through Celite. The filtrate was washed successively with 10%
Na2S2O3 and a saturated NaCl solution. After evaporation of
the solvent the residue was chromatographed (0 f 20% ethyl
acetate in pentane) to provide 38 (1.07 g, 77%) as an oil: [R]D
+60.6° (c 0.8, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.50-7.15
(m, 35H), 5.85 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.51 (d, 1H,
J ) 3.9 Hz), 5.26 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.13 (ddd,
1H, J ) 10.4, 3.1, 1.3 Hz), 4.95 (d, 2H, J ) 11.6 Hz), 4.81 (d,
1H, J ) 12.1 Hz), 4.74 (d, 1H, J ) 12.1 Hz), 4.68 (d, 1H, J )
11.7 Hz), 4.64 (s, 1H), 4.63 (d, 1H, J ) 11.0 Hz), 4.60 (d, 1H,
J ) 11.1 Hz), 4.48 (dd, 1H, J ) 11.9, 1.7 Hz), 4.36 (dd, 1H, J
) 11.9, 4.0 Hz), 4.28 (d, 1H, J ) 11.0 Hz), 4.13 (m, 2H), 4.06
(dd, 1H, J ) 9.5, 3.9 Hz), 4.05 (m,1H), 3.91 (d, 1H, J ) 2.3
Hz), 3.86 (dd, 1H, J ) 9.6, 9.5 Hz), 3.82 (dd, 1H, J ) 6.4, 6.1
Hz), 3.76 (dd, 2H, J ) 9.5, 2.6 Hz and J ) 9.5, 2.6 Hz), 3.65
(ddd, 1H, J ) 9.6, 4.0, 1.7 Hz), 3.46 (dd, 1H, J ) 9.6, 6.1 Hz),
3.39 (dd, 1H, J ) 9.6, 6.4 Hz), 3.36 (m, 1H), 3.27 (s, 3H), 3.26
(m, 1H), 3.01 (t, 2H, J ) 6.6 Hz), 2.89 (s, 3H), 1.55-1.15 (m,
10H); 13C NMR (75 MHz, CDCl3) δ 144.4, 138.8, 138.7, 138.5,
138.2, 134.4, 128.6, 128.3, 128.3, 128.2, 128.2, 127.7, 127.6,
127.3, 127.1, 126.7, 117.1, 100.2, 97.3, 86.2, 80.0, 77.9, 76.3,
74.9, 74.9, 74.7, 73.8, 72.6, 71.6, 71.6, 71.3, 71.2, 70.5, 69.9,
69.8, 69.3, 63.5, 54.9, 37.9, 29.9, 29.6, 29.3, 26.2, 26.0. Anal.
Calcd for C71H82O14S (1191.48): C,71.57; H, 6.94; S, 2.69.
Found: C, 71.74; H, 6.92; S, 2.67.
Meth yl 2-O-[2′,3′,4′-Tr i-O-ben zyl-6′-O-(7′′-h yd r oxyh ep -
tyl)-r-D-galactopyr an osyl]-3-O-allyl-4-O-ben zyl-6-O-m eth -
a n esu lfon yl-r-D-m a n n op yr a n osid e (41). Disaccharide 38
(855 mg, 0.71 mmol) was dissolved in 9:1 MeOH:EtOAc (10
mL), and a catalytic amount of p-toluensulfonic acid was
added. The reaction mixture was stirred for 6 h at room
temperature. Triethylamine (200 µL) was added, solvents
were evaporated, and the residue was purified by chromatog-
raphy (6:4 pentane-EtOAc) to provide 41 (579 mg, 85%) as
an oil: [R]D + 77.5° (c 2.0, CHCl3); 1H NMR (360 MHz, CDCl3)
δ 7.48-7.27 (m, 20H), 5.87 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz),
5.50 (d, 1H, J ) 3.8 Hz), 5.26 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz),
5.15 (ddd, 1H, J ) 10.4, 3.1, 1.3 Hz), 4.96 (d, 1H, J ) 11.5
Hz), 4.95 (d, 1H, J ) 11.7 Hz), 4.81 (d, 1H, J ) 12.2 Hz), 4.74
(d, 1H, J ) 12.2 Hz), 4.68 (d, 1H, J ) 11.7 Hz), 4.66 (s, 1H),
4.64 (d, 1H, J ) 10.9 Hz), 4.60 (d, 1H, J ) 11.5 Hz), 4.49 (dd,
1H, J ) 11.8, 1.4 Hz), 4.36 (dd, 1H, J ) 11.8 Hz, 4.1 Hz), 4.29
(d, 1H, J ) 10.9 Hz), 4.15 (dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3
Hz), 4.08 (m, 2H), 4.06 (dd, 1H, J ) 9.7, 3.8 Hz), 3.92 (d, 1H,
J ) 2.7 Hz), 3.87 (dd, 1H, J ) 9, 9.7 Hz), 3.84 (dd, 1H, J )
6.4, 5.9 Hz), 3.77 (dd, 2H, J ) 9.7, 2.7 Hz and J ) 9.7, 2.7 Hz),
3.67 (ddd, 1H, J ) 9.8, 4.0, 1.4 Hz), 3.61 (t, 2H, J ) 6.6 Hz),
3.47 (dd, 1H, J ) 9.5, 6.4 Hz), 3.41 (dd, 1H, J ) 9.5, 5.9 Hz),
3.39 (dt, 1H, J ) 9.5, 6.5 Hz), 3.30 (s, 3H), 3.29 (dt, 1H, J )
9.5, 6.7 Hz), 2.92 (s, 3H), 1.64-1.22 (m, 10H); 13C NMR (75
MHz, CDCl3) δ 138.6, 138.5, 138.3, 138.0, 134.3, 128.2, 128.1,
128.0, 128.0, 127.5, 127.4, 127.4, 127.3, 127.1, 127.1, 126.9,
116.9, 100.1, 97.2, 79.8, 77.7, 76.1, 74.7, 74.7, 74.5, 73.6, 72.4,
71.4, 71.3, 71.2, 71.1, 70.3, 69.7, 69.6, 69.2, 62.4, 54.7, 37.7,
Evaporation of the solvent and chromatography (85:15 pen-
tane-EtOAc) gave 44 (120 mg, 34%) as an oil: [R]D +49.8° (c
1.6, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.50-7.15 (m, 20H),
5.90 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.20 (ddd, 1H, J ) 17.2,
3.1, 1.6 Hz), 5.02 (ddd, 1H, J ) 10.4, 3.1, 1.3 Hz, 1H), 4.95 (d,
1H, J ) 3.6 Hz), 4.94 (d, 1H, J ) 11.5 Hz), 4.91 (d, 1H, J )
1.8 Hz), 4.90 (d, 1H, J ) 11.0 Hz), 4.83 (d, 1H, J ) 12.0 Hz),
4.76 (d, 1H, J ) 12.0 Hz), 4.74 (d, 1H, J ) 12.5 Hz), 4.72 (d,
1H, J ) 12.5 Hz), 4.63 (d, 1H, J ) 11.5 Hz), 4.55 (d, 1H, J )
11.0 Hz), 4.14 (m, 1H), 4.13 (dd, 1H, J ) 8.1, 5.8 Hz), 4.05
(dd, 1H, J ) 9.9, 3.6 Hz), 4.02 (m, 1H), 3.97 (bs, 1H), 3.98 (dd,
1H, J ) 9.9, 2.7 Hz), 3.82 (dd, 1H, J ) 9.0, 3.2 Hz), 3.79 (dd,
1H, J ) 3.2, 1.8 Hz), 3.73 (d, 1H, J ) 10.1 Hz), 3.66 (m, 2H),
3.51 (ddd, 1H, J ) 9.7, 6.5, 6.2 Hz), 3.49 (dd, 1H, J ) 10.9, 8.1
Hz), 3.47 (ddd, 1H, J ) 9.7, 6.3, 6.3 Hz), 3.42 (ddd, 1H, J )
9.7, 6.1, 6.1 Hz), 3.41 (dd, 1H, J ) 10.1, 5.7 Hz), 3.38 (dd, 1H,
J ) 10.9, 5.8 Hz), 3.36 (ddd, 1H, J ) 9.6, 6.7, 6.7 Hz), 3.31 (s,
3H), 1.60-1.26 (m, 10H); FABMS calcd for [C51H64O11Na]
875.4, found 875.2. Anal. Calcd for C50H62O11: C, 71.81; H,
7.56. Found: C, 71.82; H, 7.61.
Meth yl 2-O-(2′,3′,4′-Tr i-O-ben zyl-r-D-galactopyr an osyl)-
4-O-b en zyl-6,6′-d i-O-(h ep t a n e-1,7-d iyl)-r-D-m a n n op yr a -
n osid e (47). A solution of disaccharide 44 (290 mg, 0.34
mmol) in dry DMSO (3 mL) was heated at 80 °C, and KOtBu
(153 mg, 1.35 mmol) was added. After 2 h, the isomerization
was complete. The mixture was cooled to room temperature,
diluted with CH2Cl2, washed with water, and dried (Na2SO4).
The solvent was evaporated, and the residue was redissolved
in 9:1 acetone-water (23 mL). Mercuric oxide (36 mg, 0.16
mmol) and mercuric chloride (2.0 g, 7.36 mmol) were added,
and the solution was stirred for 30 min. The solvent was
evaporated, and the residue was purified by chromatography
(80:20 pentane-EtOAc) to afford 47 (235 mg, 85%) as an oil:
[R]D +67.3° (c 0.6, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.50-
7.15 (m, 20H), 4.92 (d, 1H, J ) 11.4 Hz), 4.89 (d, 1H, J ) 11.3
Hz), 4.86 (d, 1H, J ) 11.8 Hz), 4.77 (d, 1H, J ) 3.7 Hz), 4.75
(d, 1H, J ) 1.7 Hz), 4.74 (bs, 2H), 4.68 (d, 1H, J ) 11.8 Hz),
4.64 (d, 1H, J ) 11.5 Hz), 4.57 (d, 1H, J ) 11.3 Hz), 4.06 (dd,
1H, J ) 6.7, 6.6 Hz), 4.00 (dd, 1H, J ) 10.1, 3.7 Hz), 3.95(dd,
1H, J ) 2.7, 0.9 Hz), 3.94 (dd, 1H, J ) 9.2, 3.8 Hz), 3.85 (dd,
1H, J ) 9.9, 2.7 Hz), 3.70 (dd, 1H, J ) 10.1, 1.8 Hz), 3.64 (dd,
1H, J ) 3.8, 1.7 Hz), 3.59 (ddd, 1H, J ) 9.9, 6.1, 1.8 Hz), 3.52
(ddd, 1H, J ) 9.7, 6.5, 6.2 Hz), 3.48-3.40 (m, 5H), 3.31 (dd,
1H, J ) 9.9, 9.2 Hz), 3.31 (ddd, 1H, J ) 9.5, 6.3, 6.3 Hz), 3.30
(s, 3H), 1.60-1.26 (m, 10H). Anal. Calcd for (C48H60O11): C,
70.91; H, 7.44. Found: C, 70.92; H, 7.50.
Meth yl 2-O-(2′′,3′′,4′′-Tr i-O-ben zyl-r-D-ga la ctop yr a n o-
syl)-3-O-(2′,4′-d i-O-ben zyl-3′,6′-d id eoxy-r-D-xylo-h exop y-
r a n osyl)-4-O-ben zyl-6,6′′-d i-O-(h ep ta n e-1,7-d iyl)-r-D-m a n -
n op yr a n osid e (50). The disaccharide alcohol 47 (119 mg,
0.14 mmol) and the 3,6-dideoxyhexose thioglycoside 11 (250
mg, 0.67 mmol) were dried in vacuo with powdered and freshly
activated 4 Å molecular sieves over P2O5 overnight. The
mixture was suspended in dry CH2Cl2 (5 mL), cooled to -45
°C, and stirred for 20 min. N-Iodosuccinimide (168 mg, 0.71
mmol) and a solution of silver triflate (17 mg, 0.07 mmol) in
dry toluene (200 µL) were added rapidly, dropwise, and after
30 min the reaction was quenched with triethylamine. The
reaction was then diluted with CH2Cl2 and filtered, and the
filtrate was washed successively with Na2S2O3 and a saturated
NaCl solution and dried (Na2SO4). After evaporation of
solvent, the residue was purified by chromatography (85:15
pentane-EtOAc) to afford 50 (89 mg, 54%) as an oil: [R]D
+83.3° (c 1.5, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.50-7.15
(m, 30H), 5.09 (d, 1H, J ) 11.8 Hz), 5.03 (d, 1H, J ) 3.3 Hz),
4.97 (bs, 1H), 4.94 (d, 1H, J ) 12.2 Hz), 4.91 (d, 1H, J ) 2.0
Hz), 4.90 (d, 1H, J ) 11.3 Hz), 4.75 (bs, 2H), 4.63 (d, 1H, J )
12.2 Hz), 4.62 (d, 1H, J ) 11.5 Hz), 4.59 (d, 1H, J ) 11.8 Hz),
4.38 (d, 1H, J ) 12.4 Hz), 4.32 (d, 1H, J ) 12.4 Hz), 4.25 (d,
1H, J ) 12.2 Hz), 4.23 (dd, 1H, J ) 8.2, 5.8 Hz), 4.09 (dd, 1H,
J ) 8.8, 2.9 Hz), 4.07 (m, 2H), 4.06 (d, 1H, J ) 12.2 Hz), 4.05
(m, 1H), 4.02 (bs, 1H), 3.84 (dd, 1H, J ) 2.9, 2.0 Hz), 3.72 (dd,
1H, J ) 9.9, 8.8 Hz), 3.69 (m 1H), 3.66 (m, 1H), 3.55 (dd, 1H,
J ) 9.9, 5.8 Hz), 3.45-3.40 (m, 4H), 3.34 (dd, 1H, J ) 9.9, 5.3
Hz), 3.32 (s, 3H), 3.31 (dd, 1H, J ) 9.3, 5.6 Hz), 2.43 (bs, 1H),
32.7, 29.4, 29.0, 25.8, 25.4. Anal. Calcd for C52H68O14
S
(949.16): C, 65.80; H, 7.22; S, 3.38. Found: C, 65.41; H, 7.39;
S, 3.56.
Meth yl 2-O-(3′-O-Allyl-4′-O-ben zyl-r-D-ga la ctop yr a n o-
syl)-2,3,4-tr i-O-ben zyl-6,6′-di-O-(h eptan e-1,7-diyl)-r-D-m an -
n op yr a n osid e (44). A solution of disaccharide 41 (397 mg,
0.42 mmol) in dry THF (19 mL) was slowly added to a boiling
mixture of NaH (130 mg, 5.45 mmol) and Cs2CO3 (192 mg,
0.54 mmol) in dry THF (22 mL) over a 2 h period, and the
reaction mixture was then refluxed for 24 h. After an excess
of NaH was decomposed with MeOH, the solvent was evapo-
rated under reduced pressure and the resulting residue taken
up in CH2Cl2 and washed with a saturated NaCl solution.

Synthesis of Tethered Trisaccharides
J . Org. Chem., Vol. 63, No. 18, 1998 6299
1.70 (m, 2H), 1.55-1.30 (m, 10H), 0.98 (d, 3H, J ) 6.5 Hz,
1H). Anal. Calcd for C68H82O14: C, 72.70; H, 7.36. Found:
C, 72.68; H, 7.42.
Triethylamine (200 µL) was added, solvents were evaporated,
and the residue was purified by chromatography (6:4 pentane-
EtOAc) to provide 42 (912 mg, 85%) as an oil: [R]D + 75.6° (c
2.3, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.48-7.27 (m, 20H),
5.88 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.50 (d, 1H, J ) 3.9
Hz), 5.26 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.14 (ddd, 1H, J )
10.4, 3.1, 1.3 Hz), 4.96 (d, 1H, J ) 11.4 Hz), 4.95 (d, 1H, J )
11.7 Hz), 4.81 (d, 1H, J ) 12.2 Hz), 4.74 (d, 1H, J ) 12.2 Hz),
4.68 (d, 1H, J ) 11.5 Hz), 4.66 (s, 1H), 4.63 (d, 1H, J ) 11.1
Hz), 4.60 (d, 1H, J ) 11.5 Hz), 4.49 (dd, 1H, J ) 11.8, 1.6 Hz),
4.36 (dd, 1H, J ) 11.8, 4.1 Hz), 4.28 (d, 1H, J ) 10.9 Hz), 4.15
(dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.08 (m, 2H), 4.06 (dd,
1H, J ) 10.1, 3.9 Hz), 3.92 (d, 1H, J ) 2.3 Hz), 3.87 (dd, 1H,
J ) 9.8, 9.6 Hz), 3.83 (dd, 1H, J ) 6.4, 6.0 Hz), 3.77 (dd, 2H,
J ) 9.8, 2.7 Hz and J ) 9.8, 2.7 Hz), 3.66 (ddd, 1H, J ) 9.8,
4.1, 1.6 Hz), 3.61 (t, 2H, J ) 6.4 Hz), 3.47 (dd, 1H, J ) 9.7, 6.4
Hz), 3.40 (dd, 1H, J ) 9.7, 6.0 Hz), 3.39 (dt, 1H, J ) 9.5, 6.5
Hz), 3.30 (s, 3H), 3.29 (dt, 1H, J ) 9.3, 6.8 Hz), 2.92 (s, 3H),
1.64-1.22 (m, 12H); 13C NMR (75 MHz, CDCl3) δ 138.7, 138.5,
138.4, 138.0, 134.3, 128.2, 128.2, 128.1, 127.6, 127.5, 127.4,
127.2, 127.1, 127.0, 116.9, 100.1, 97.2, 79.8, 77.8, 76.1, 74.8,
74.7, 74.5, 73.7, 72.5, 71.5, 71.4, 71.2, 71.1, 70.3, 69.8, 69.7,
69.2, 62.5, 54.7, 37.7, 32.5, 29.5, 29.2, 29.1, 25.8, 25.5. Anal.
Calcd for C53H70O14S (963.19): C, 66.09; H, 7.33; S, 3.33.
Found: C, 65.93; H, 7.55; S, 3.42.
Meth yl 2-O-(3′-O-Allyl-4′-O-ben zyl-r-D-ga la ctop yr a n o-
syl)-2,3,4-tr i-O-ben zyl-6,6′-d i-O-(octa n e-1,8-d iyl)-r-D-m a n -
n op yr a n osid e (45). Meth od A. A solution of disaccharide
42 (322 mg, 0.33 mmol) in dry THF (18 mL) was slowly added
to a boiling mixture of NaH (104 mg, 4.35 mmol) and Cs2CO3
(153 mg, 0.44 mmol) in dry THF (15 mL) over a 2 h period,
and the reaction mixture was then refluxed for 24 h. After
an excess of NaH was decomposed with MeOH, the solvent
was evaporated under reduced pressure and the resulting
residue taken up in CH2Cl2 and washed with a saturated NaCl
solution. Evaporation of the solvent and chromatography (85:
15 pentane-EtOAc) gave 45 (101 mg, 35%) as an oil.
Meth od B. A solution of disaccharide 53 (377 mg, 0.39
mmol) in dry THF (19 mL) was slowly added to a boiling
mixture of NaH (121 mg, 5.07 mmol) and Cs2CO3 (179 mg,
0.507 mmol) in dry THF (20 mL) over a 2 h period. The
reaction mixture was refluxed for 24 h. After an excess of NaH
was decomposed with MeOH, the solvent was evaporated
under reduced pressure and the resulting residue taken up in
CH2Cl2 and washed with a saturated NaCl solution. Evapora-
tion of the solvent and chromatography gave 45 (208 mg, 61%
yield) as an oil: [R]D +52.6° (c 1.0, CHCl3); 1H NMR (500 MHz,
CDCl3) δ 7.50-7.15 (m, 20H), 5.82 (ddd, 1H, J ) 17.2, 10.4,
5.7 Hz), 5.20 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.03 (ddd, 1H, J
) 10.4, 3.1, 1.3 Hz), 5.01 (d, 1H, J ) 3.8 Hz), 4.94 (d, 1H, J )
11.6 Hz), 4.88 (d, 1H, J ) 11.1 Hz), 4.86 (d, 1H, J ) 1.4 Hz),
4.83 (d, 1H, J ) 11.9 Hz), 4.78 (d, 1H, J ) 11.6 Hz), 4.75 (d,
1H, J ) 12.1 Hz), 4.69 (d, 1H, J ) 11.6 Hz), 4.62 (d, 1H, J )
11.6 Hz), 4.55 (d, 1H, J ) 11.1 Hz), 4.12 (dddd, 1H, J ) 12.6,
5.6, 1.6, 1.3 Hz), 4.08 (m, 2H), 4.03 (dddd, 1H, J ) 12.6, 5.6,
1.6, 1.3 Hz), 3.98 (dd, 1H, J ) 2.9, 0.9 Hz), 3.95 (dd, 1H, J )
9.9, 2.9 Hz), 3.81 (m, 1H), 3.79 (dd, 1H, J ) 9.0, 3.1 Hz), 3.70
(d, 1H, J ) 10.4 Hz), 3.65 (m, 2H), 3.52 (dt, 1H, J ) 9.5, 5.8
Hz), 3.44-3.36 (m, 6H), 3.31 (s, 3H), 1.60-1.26 (m, 12H);
FABMS calcd for [C52H66O11Na] 889.4, found 889.3.
Meth yl 2-O-(2′,3′,4′-Tr i-O-ben zyl-r-D-galactopyr an osyl)-
4-O-ben zyl-6,6′-d i-O-(octa n e-1,8-d iyl)-r-D-m a n n op yr a n o-
sid e (48). A solution of disaccharide 45 (219 mg, 0.25 mmol)
in dry DMSO (2 mL) was heated at 80 °C, and KOtBu (113
mg, 1.01 mmol) was added. After 2 h, the isomerization was
complete. The mixture was cooled to room temperature,
diluted with CH2Cl2, washed with water, and dried (Na2SO4).
The solvent was evaporated, and the residue was redissolved
in 9:1 acetone-water (20 mL). Mercuric oxide (25 mg, 0.11
mmol) and mercuric chloride (1.5 g, 5.52 mmol) were added,
and the solution was stirred for 30 min. The solvent was
evaporated, and the residue was purified by chromatography
(80:20 pentane-EtOAc) to afford 48 (179 mg, 85%) as an oil:
[R]D +68.0° (c 0.9, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.50-
7.15 (m, 20H), 4.91 (d, 1H, J ) 11.6 Hz), 4.87 (d, 1H, J ) 11.5
Meth yl 2-O-(r-D-Ga la ctop yr a n osyl)-3-O-(3′,6′-d id eoxy-
r-D-xylo-h exop yr a n osyl)-6,6′′-d i-O-(h ep ta n e-1,7-d iyl)-r-D-
m a n n op yr a n osid e (3). A stirred solution of 50 (65 mg, 0.06
mmol) in acetic acid (7 mL) was hydrogenated over 10% Pd/C
(73 mg) under a flow of H2 overnight. The catalyst was
removed by filtration and the solvent evaporated. Chroma-
tography (85:15 CH2Cl2-MeOH) on Iatrobeads afforded 3 (28
1
mg, 83%) as a white solid: [R]D +99.8° (c 0.5, H2O); H NMR
(500 MHz, D2O) δ 5.07 (d, 1H, J 1,2 ) 3.7 Hz, H1′), 5.06 (d, 1H,
J 1,2 ) 1.8 Hz, H1), 5.02 (d, 1H, J 1,2 ) 4.0 Hz, H1′′), 4.28 (m,
1H, H5′′), 4.09 (m, H-5′), 4.02 (m, 1H, J 2,3ax ) 9.3, J 2,3eq ) 8.4
Hz, H2′), 3.98 (dd, 1H, J 4,5 ) 0.9, Hz, H4′′), 3.94 (m 1H, J 3,4
)
9.7 Hz, H3), 3.94 (m, J 5,6a ) 1.4 Hz, H6a), 3.91 (ddd, 1H, J 3,4
) 3.4, Hz, H3′′) 3.88 (dd, 1H, J 2,3 ) 3.2 Hz, H2), 3.86 (m, J 4,5
) 1.3 Hz, H-4′), 3.78 (dd, 1H, J 4,5 ) 9.7 Hz, H4), 3.75 (dd, 1H,
J 2,3 ) 10.4 Hz, H2′′), 3.72 (m, H5), 3.70 (dd, 1H, J 5,6a ) 7.6,
Hz, H6a′′), 3.70 (m, 1H, OCH2), 3.66 (m, 1H, OCH2), 3.63 (dd,
1H, J 5,6a ) 4.1, Hz, H6b′′), 3.62 (m, 1H, OCH2), 3.59 (m, J 5,6b
) 8.1 Hz, H6b), 3.52 (m, 1H, OCH2), 1.97 (m, 2H, J 3eq,4 ) J 3ax,4
) 3.1 Hz, H-3′), 1.7-1.3 (m, 10H, OCH2(CH2)5CH2O), 1.18 (d,
3H, J 5,6 ) 6.7 Hz, H-6′). 13C NMR (125 MHz, D2O) δ 103.3
1
1
(1C, J C,H ) 169.2 Hz, C1′′), 101.6 (1C, J C,H ) 170.6 Hz, C1′),
1
100.0 (1C, J C,H ) 173.2 Hz, C1), 82.4 (1C, C2), 78.4 (1C, C3),
73.0 (1C, C5), 72.1 (1C, OCH2), 71.8 (1C, OCH2), 70.8 (1C, C6′′),
70.6 (1C, C6), 70.5 (1C, C4′′), 70.2 (1C, C3′′), 69.9 (1C, C5′′),
69.5 (1C, C2′′), 69.1 (1C, C4′), 67.9 (1C, C4), 67.5 (1C, C5′),
64.2 (1C, C2′), 33.7 (1C, C3′), 28.4 (1C, -CH2-), 28.2 (1C, -CH2-
), 27.4 (1C, -CH2-), 25.8 (1C, -CH2-), 25.6 (1C, -CH2-), 16.2 (1C,
C6′); ES HRMS calcd for [C26H46O14Na] 605.2785, found
605.2766.
Meth yl 3-O-Allyl-2-O-[2′,3′,4′-tr i-O-ben zyl-6′-O-(8′′-tr i-
tyloxyoctyl)-r-D-ga la ctop yr a n osyl]-4-O-ben zyl-6-O-m eth -
a n esu lfon yl-r-D-m a n n op yr a n osid e (39). The alcohol 5 (495
mg, 1.23 mmol) and the thioglycoside 8 (1.23 g, 1.42 mmol)
were dried in vacuo with powdered 4 Å molecular sieves over
P2O5 overnight. The mixture was suspended in CH2Cl2 (18
mL) under an Ar atmosphere and stirred for 2 h at room
temperature. N-Iodosuccinimide (639 mg, 2.84 mmol) was
added, and the suspension was stirred for 10 min before rapid,
dropwise addition of a saturated solution of triflic acid in ca.
0.15 M CH2Cl2 (1.4 mL, 0.21 mmol). The reaction was
quenched with triethylamine, diluted with CH2Cl2, and filtered
through Celite. The filtrate was washed successively with 10%
Na2S2O3 and a saturated NaCl solution. After evaporation of
the solvent the residue was chromatographed (0 f 20% ethyl
acetate in pentane) to provide 39 (1.12 g, 76%) as an oil: [R]D
+50.5° (c 1.7, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.50-7.15
(m, 35H), 5.88 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.51 (d, 1H,
J ) 3.8 Hz), 5.25 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.14 (ddd,
1H, J ) 10.4, 3.1, 1.3 Hz), 4.95 (d, 2H, J ) 11.6 Hz), 4.80 (d,
1H, J ) 12.2 Hz), 4.74 (d, 1H, J ) 12.2 Hz), 4.68 (d, 1H, J )
11.6 Hz), 4.65 (s, 1H), 4.63 (d, 1H, J ) 11.3 Hz), 4.60 (d, 1H,
J ) 11.5 Hz), 4.49 (dd, 1H, J ) 11.9, 1.7 Hz), 4.36 (dd, 1H, J
) 11.9, 4.0 Hz), 4.28 (d, 1H, J ) 10.9 Hz), 4.15 (m, 1H), 4.10
(m, 2H), 4.06 (dd, 1H, J ) 9.9, 3.8 Hz), 3.92 (d, 1H, J ) 2.6
Hz), 3.87 (dd, 1H, J ) 9.6, 9.5 Hz), 3.83 (dd, 1H, J ) 6.5, 6.3
Hz), 3.76 (dd, 2H, J ) 9.9, 2.6 Hz and J ) 9.5, 2.6 Hz), 3.66
(ddd, 1H, J ) 9.7, 4.0, 1.7 Hz), 3.47 (dd, 1H, J ) 9.6, 6.3 Hz),
3.39 (dd, 1H, J ) 9.6, 6.5 Hz), 3.37 (m, 1H), 3.28 (s, 3H), 3.26
(m, 1H), 3.02 (t, 2H, J ) 6.6 Hz), 2.90 (s, 3H), 1.15-1.55 (m,
12H); 13C NMR (75 MHz, CDCl3) δ 144.4, 138.8, 138.7, 138.5,
138.2, 134.4, 128.6, 128.3, 128.3, 128.2, 128.2, 128.0, 127.7,
127.6, 127.4, 127.3, 126.7, 117.1, 100.2, 97.3, 86.2, 80.0, 77.9,
76.3, 74.9, 74.9, 74.7, 73.8, 72.6, 71.6, 71.6, 71.3, 71.2, 70.5,
69.9, 69.8, 69.3, 63.5, 54.9, 37.8, 29.9, 29.7, 29.5, 29.3, 26.2,
26.0; FABMS calcd for [C72H84O14SNa] 1227.5, found 1227.7.
Meth yl 3-O-Allyl-2-O-[2′,3′,4′-tr i-O-ben zyl-6′-O-(8′′-h y-
d r oxyoctyl)-r-D-ga la ctop yr a n osyl]-4-O-ben zyl-6-O-m eth -
a n esu lfon yl-r-D-m a n n op yr a n osid e (42). Disaccharide 39
(1.34 g, 1.11 mmol) was dissolved in 9:1 MeOH:EtOAc (10 mL),
and a catalytic amount of p-toluensulfonic acid was added. The
reaction mixture was stirred for 6 h at room temperature.

6300 J . Org. Chem., Vol. 63, No. 18, 1998
Alibe´s and Bundle
Hz), 4.86 (d, 1H, J ) 11.3 Hz), 4.81 (d, 1H, J ) 3.8 Hz), 4.74
(b, 2H), 4.73 (m, 1H), 4.68 (d, 1H, J ) 11.6 Hz), 4.62 (d, 1H, J
) 11.6 Hz), 4.54 (d, 1H, J ) 10.8 Hz), 4.02 (dd, 1H, J ) 7.3,
5.5 Hz), 4.01 (dd, 1H, J ) 9.9, 3.7 Hz), 3.96 (dd, 1H, J ) 2.9,
0.9 Hz), 3.94 (m, 1H), 3.87 (dd, 1H, J ) 9.9, 2.9 Hz), 3.70 (dd,
1H, J ) 10.4, 1.8 Hz), 3.65 (dd, 1H, J ) 3.8, 1.7 Hz), 3.60 (ddd,
1H, J ) 9.9, 6.5, 1.8 Hz), 3.58 (b, 1H), 3.52 (ddd, 1H, J ) 9.7,
6.5, 6.2 Hz), 3.48-3.40 (m, 6H), 3.30 (dd, 1H, J ) 9.9, 9.2 Hz),
3.30 (s, 3H), 1.60-1.26 (m, 12H). Anal. Calcd for
(C49H62O11): C, 71.16; H, 7.56. Found: C, 71.08; H, 7.57.
Meth yl 2-O-(2′′,3′′,4′′-Tr i-O-ben zyl-r-D-ga la ctop yr a n o-
syl)-3-O-(2′,4′-d i-O-ben zyl-3′,6′-d id eoxy-r-D-xylo-h exop y-
r a n osyl)-4-O-ben zyl-6,6′′-d i-O-(octa n e-1,8-d iyl)-r-D-m a n -
n op yr a n osid e (51). The disaccharide alcohol 48 (136 mg,
0.16 mmol) and the 3,6-dideoxyhexose thioglycoside 11 (281
mg, 0.75 mmol) were dried in vacuo with powdered and freshly
activated 4 Å molecular sieves over P2O5 overnight. The
mixture was suspended in dry CH2Cl2 (5.5 mL), cooled to -45
°C, and stirred for 20 min. N-Iodosuccinimide (178 mg, 0.79
mmol) and a solution of silver triflate (20 mg, 0.08 mmol) in
dry toluene (200 µL) were added rapidly, dropwise, and after
30 min the reaction was quenched with triethylamine. The
reaction was then diluted with CH2Cl2 and filtered, and the
filtrate was washed successively with Na2S2O3 and a saturated
NaCl solution and dried (Na2SO4). After evaporation of
solvent, the residue was purified by chromatography (84:16
pentane-EtOAc) to afford 51 (116 mg, 62%) as an oil: [R]D
+82.1° (c 0.8, CHCl3); 1H NMR (500 MHz, CDCl3) δ 7.15-7.50
(m, 30H), 5.09 (d, 1H, J ) 11.8 Hz), 5.04 (d, 1H, J ) 3.3 Hz),
5.00 (d, 1H, J ) 2.9 Hz), 4.94 (d, 1H, J ) 12.0 Hz), 4.91 (d,
1H, J ) 11.4 Hz), 4.89 (d, 1H, J ) 1.8 Hz), 4.75 (b, 2H), 4.65
(d, 1H, J ) 12.1 Hz), 4.61 (d, 1H, J ) 11.4 Hz), 4.59 (d, 1H, J
) 11.6 Hz), 4.38 (d, 1H, J ) 12.4 Hz), 4.31 (d, 1H, J ) 12.5
Hz), 4.27 (d, 1H, J ) 12.2 Hz), 4.19 (dd, 1H, J ) 7.0, 6.7 Hz),
4.10 (m, 2H), 4.08-4.05 (m, 3H), 4.02 (b, 1H), 3.85 (dd, 1H, J
) 2.7, 2.0 Hz), 3.75 (dd, 1H, J ) 9.9, 9.5 Hz), 3.70 (ddd, 1H, J
) 9.9, 6.1, 1.2 Hz), 3.67 (m, 1H), 3.63 (dd, 1H, J ) 10.0, 1.2
Hz), 3.50-3.35 (m, 6H), 3.32 (s, 3H), 3.31 (ddd, 1H, J ) 9.5,
6.4, 6.4 Hz), 2.48 (b, 1H), 1.70 (m, 2H), 1.55-1.25 (m, 12H),
0.99 (d, 3H, J ) 6.7 Hz). Anal. Calcd for C69H84O14: C, 72.86;
H, 7.44. Found: C,72.80; H, 7.43.
under an Ar atmosphere and stirred for 2 h at room temper-
ature. N-Iodosuccinimide (729 mg, 3.24 mmol) was added and
the suspension stirred for 10 min before a solution of triflic
acid in CH2Cl2 (0.15 M, 1.62 mL) was added rapidly, dropwise.
After being stirred for 30 min, the reaction was quenched with
triethylamine, diluted with CH2Cl2, and filtered. The filtrate
was washed with 10% Na2S2O3 and a saturated NaCl solution.
Evaporation of the solvent and chromatography (75:25 EtOAc-
pentane) afforded disaccharide 52 (902 mg, 82%) as an oil: [R]D
+51.1° (c 1.8, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.50-6.90
(m, 35H), 5.90 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.48 (d, 1H,
J ) 2.6 Hz), 5.24 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.11 (ddd,
1H, J ) 10.4, 3.1, 1.3 Hz), 4.97 (d, 2H, J ) 11.9 Hz), 4.90 (d,
1H, J ) 11.8 Hz), 4.82 (d, 1H, J ) 1.8 Hz), 4.76 (d, 1H, J )
11.3 Hz), 4.71 (d, 1H, J ) 11.7 Hz), 4.64 (d, 1H, J ) 11.1 Hz),
4.63 (d, 1H, J ) 11.8 Hz), 4.38 (d, 1H, J ) 11.3 Hz), 4.31 (d,
1H, J ) 11.2 Hz),4.20 (dd, 1H, J ) 2.6, 1.2 Hz), 4.19-4.15 (m,
1H), 4.13 (t, 2H, J ) 6.6 Hz), 4.12 (m, 1H), 4.02 (bm, 2H), 3.90
(d, 1H, J ) 1.8 Hz), 3.89 (dd, 1H, J ) 9.6, 9.3 Hz), 3.80 (dd,
1H, J ) 9.3, 2.6 Hz), 3.73-3.63 (m, 3H), 3.53 (dt, 1H, J ) 9.2,
6.6 Hz), 3.40 (dt, 1H, J ) 9.2, 6.8 Hz), 3.39 (m, 1H), 3.29 (s,
3H), 3.03 (dd, 1H, J ) 9.2, 5.7 Hz), 2.93 (s, 3H), 1.15-1.55 (m,
12H); 13C NMR (75 MHz, CDCl3) δ 144.40, 138.82, 138.67,
138.50, 138.18, 134.42, 128.58, 128.34, 128.27, 128.21, 128.16,
128.02, 127.68, 127.59, 127.35, 127.27, 126.72, 117.05, 100.17,
97.5, 86.5, 78.4, 76.6, 76.4, 75.8, 75.1, 74.8, 74.5, 73.3, 72.1,
71.7, 71.4, 71.1, 70.0, 69.9, 63.4, 54.6, 37.0, 29.7, 29.1, 28.9,
28.8, 25.9, 25.2. Anal. Calcd for C72H84O14S (1205): C, 71.74;
H, 7.02; S, 2.66. Found: C, 71.80; H, 6.84; S, 2.75.
Meth yl 3-O-Allyl-2-O-[2′,3′,4′-tr i-O-ben zyl-r-D-ga la cto-
p yr a n osyl]-4-O-ben zyl-6-O-(m eth a n esu lfon yloxyoctyl)-r-
D-m a n n op yr a n osid e (53). Disaccharide 52 (787 mg, 0.65
mmol) was dissolved in 9:1 MeOH:EtOAc, and a catalytic
amount of p-toluenesulfonic acid was added. The reaction
mixture was stirred for 7 h. Triethylamine (100 µL) was
added, the solvents were evaporated, and the residue was
purified by chromatography (1:1 EtOAc-pentane) to afford 53
1
(505 mg, 81%) as an oil: [R]D +53.3° (c 2.2, CHCl3); H NMR
(360 MHz, CDCl3) δ 7.40-7.10 (m, 20H), 5.90 (ddd, 1H, J )
17.2, 10.4, 5.7 Hz), 5.41 (d, 1H, J ) 3.6 Hz), 5.24 (ddd, 1H, J
) 17.2, 3.1, 1.6 Hz), 5.11 (ddd, 1H, J ) 10.4, 3.1, 1.3 Hz), 4.95
(d, 1H, J ) 11.6 Hz), 4.93 (d, 1H, J ) 11.7 Hz), 4.90 (d, 1H, J
) 11.7 Hz), 4.76 (d, 1H, J ) 1.8 Hz), 4.72 (d, 1H, J ) 11.7 Hz),
4.69 (d, 1H, J ) 11.6 Hz), 4.68 (d, 1H, J ) 11.2 Hz), 4.60 (d,
1H, J ) 11.6 Hz), 4.33 (d, 1H, J ) 11.2 Hz), 4.31 (d, 1H, J )
11.2 Hz), 4.13 (m, 1H), 4.12 (t, 2H, J ) 6.6 Hz), 4.09 (m, 2H),
4.14 (dd, 1H, J ) 2.7, 1.8 Hz), 3.99 (dd, 1H, J ) 10.1, 3.6 Hz),
3.90 (m, 1H), 3.86 (b, 1H), 3.85 (dd, 1H, J ) 9.5, 9.3 Hz), 3.77
(dd, 1H, J ) 9.3, 2.7 Hz), 3.73 (dd, 1H, J ) 11.4, 6.8 Hz), 3.68-
3.59 (m, 3H), 3.45 (m, 2H), 3.36 (dt, 1H, J ) 9.2, 6.8 Hz), 3.30
(s, 3H), 2.93 (s, 3H), 1.15-1.55 (m, 12H); FABMS calcd for
[C53H70O14SNa] 985.4, found 985.3.
Meth yl 2-O-(r-D-Ga la ctop yr a n osyl)-3-O-(3′,6′-d id eoxy-
r-D-xylo-h exop yr a n osyl)-6,6′′-d i-O-(oct a n e-1,8-d iyl)-r-D-
m a n n op yr a n osid e (4). A stirred solution of 51 (81 mg, 0.07
mmol) in acetic acid (9 mL) was hydrogenated over 10% Pd/C
(93 mg) under a flow of H2 overnight. The catalyst was
removed by filtration, and the solvent was evaporated. Chro-
matography (85:15 CH2Cl2-MeOH) on Iatrobeads afforded 4
1
(38 mg, 89%) as a white solid: [R]D +105.2° (c 0.8, H2O); H
NMR (500 MHz, D2O) δ 5.10 (d, 1H, J 1,2 ) 1.6 Hz, H1), 5.08
(d, 1H, J 1,2 ) 3.8 Hz, H1′), 5.02 (d, 1H, J 1,2 ) 4.0 Hz, H1′′),
4.23 (m, 1H, H5′′), 4.09 (m, H-5′), 4.01 (m, 1H, J 2,3ax ) 10.8,
J 2,3eq ) 6.7 Hz, H2′), 3.97 (dd, 1H, J 4,5 ) 0.9, Hz, H4′′), 3.95
(m, H6a), 3.92 (m, H3), 3.90 (ddd, 1H, J 3,4 ) 3.4, Hz, H3′′),
3.89 (d, 1H, J 2,3 ) 3.1 Hz, H2), 3.86 (m, J 4,5 ) 1.2 Hz, H-4′),
3.76 (m, H4), 3.76 (m, H5), 3.75 (dd, 1H, J 2,3 ) 10.4, Hz, H2′′),
3.73 (m, 1H, OCH2), 3.67 (dd, 1H, J 5,6a ) 8.3, Hz, H6a′′), 3.62
(m, 1H, OCH2), 3.59 (dd, 1H, J 5,6a ) 3.5, Hz, H6b′′), 3.57 (m,
H6b), 3.53 (m, 1H, OCH2), 3.51 (m, 1H, OCH2), 1.98 (m, 2H,
J 3eq,4 ) J 3ax,4 ) 3.4 Hz, H-3′), 1.6-1.3 (m, 12H, OCH2(CH2)6-
CH2O), 1.18 (d, 3H, J 5,6 ) 6.7 Hz, H-6′); 13C NMR (125 MHz,
Meth yl 2-O-[2′,3′,4′-Tr i-O-ben zyl-6′-O-(1′′,1′′,1′′-tr ip h e-
n yloxy-3,6-dioxaoctan yl)-r-D-galactopyr an osyl]-3-O-allyl-
4-O-ben zyl-6-O-m eth a n esu lfon yl-r-D-m a n n op yr a n osid e
(54). The alcohol 5 (450 mg, 1.12 mmol) and the thioglycoside
12 (1.19 g, 1.37 mmol) were dried in vacuo with powdered 4 Å
molecular sieves over P2O5 overnight. The mixture was
suspended in CH2Cl2 (24 mL) under an Ar atmosphere and
stirred for 2 h at room temperature. N-Iodosuccinimide (554
mg, 2.46 mmol) was added, and the suspension was stirred
for 10 min before a saturated solution of triflic acid in ca. 0.15
M CH2Cl2 (900 µL, 0.13 mmol) was added rapidly, dropwise.
The reaction was quenched with triethylamine and diluted
with CH2Cl2, and the reaction was filtered through Celite. The
filtrate was washed successively with 10% Na2S2O3 and a
saturated NaCl solution. After evaporation of the solvent the
residue was chromatographed (2:1 pentane-EtOAc) to provide
54 (1.00 g, 74%) as an oil: [R]D +65.04° (c 2.02, CHCl3); 1H
NMR (360 MHz, CDCl3) δ 7.48-7.15 (m, 35H), 5.86 (ddd, 1H,
J ) 17.2, 10.4, 5.7 Hz), 5.51 (d, 1H, J ) 3.9 Hz), 5.25 (ddd,
1H, J ) 17.2, 3.1, 1.6 Hz), 5.13 (ddd, 1H, J ) 10.4, 3.1, 1.3
Hz), 4.94 (d, 1H, J ) 11.7 Hz), 4.93 (d, 1H, J ) 11.5 Hz), 4.78
(d, 1H, J ) 12.2 Hz), 4.72 (d, 1H, J ) 12.2 Hz), 4.68 (d, 1H, J
) 11.9 Hz), 4.64 (d, 1H, J ) 1.9 Hz), 4.62 (d, 1H, J ) 10.9 Hz),
1
1
D2O) δ 103.5 (1C, J C,H ) 170.4 Hz, C1′′), 101.5 (1C, J C,H
)
170.4 Hz, C1′), 100.2 (1C, 1J C,H ) 174.0 Hz, C1), 82.3 (1C, C2),
78.5 (1C, C3), 71.5 (OCH2), 71.4 (OCH2), 70.9 (1C, C5′′), 70.8
(1C, C6), 70.5 (1C, C4′′), 70.2 (1C, C3′′), 70.2 (1C, C6′′), 69.5
(1C, C2′′), 69.2 (1C, C4′), 68.2 (1C, C4), 68.2 (1C, C5), 67.5 (1C,
C5′), 64.2 (1C, C2′), 33.6 (1C, C3′), 28.8 (2C, -CH2-), 28.7 (2C,
-CH2-), 25.4 (1C, -CH2-), 25.3 (1C, -CH2-), 16.2 (1C, C6′); ES
HRMS calcd for [C27H48O14Na] 619.2942, found 619.2947.
Meth yl 3-O-Allyl-2-O-[2′,3′,4′-tr i-O-ben zyl-6′-O-tr ityl-r-
D-ga la ctop yr a n osyl]-4-O-ben zyl-6-O-(8′′-m eth a n esu lfon y-
loxyoctyl)-r-D-m a n n op yr a n osid e (52). Alcohol 9 (428 mg,
0.90 mmol) and thioglycoside 10 (1.19 g, 1.61 mmol) were dried
in vacuo with powdered 4 Å molecular sieves over P2O5
overnight. The mixture was suspended in CH2Cl2 (19 mL)

Synthesis of Tethered Trisaccharides
J . Org. Chem., Vol. 63, No. 18, 1998 6301
4.60 (d, 1H, J ) 11.5 Hz), 4.48 (dd, 1H, J ) 11.8, 1.7 Hz), 4.36
(dd, 1H, J ) 11.8, 4.0 Hz), 4.26 (d, 1H, J ) 10.9 Hz), 4.13 (dddd,
1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.09 (dd, 1H, J ) 2.5, 1.9 Hz),
4.06 (m, 1H), 4.05 (dd, 1H, J ) 9.8, 3.9 Hz), 3.94 (d, 1H, J )
2.0 Hz), 3.86 (t, 1H, J ) 5.5 Hz), 3.86 (dd, 1H, J ) 9.7, 9.5
Hz), 3.75 (dd, 2H, J ) 9.8, 2.0 Hz and J ) 9.7, 2.5 Hz), 3.42-
3.68 (m, 11H), 3.27 (s, 3H), 3.28 (m, 1H), 3.20 (t, 2H, J ) 5.3
Hz), 2.90 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 144.0, 138.8,
138.6, 138.5, 138.1, 134.4, 128.6, 128.3, 128.3, 128.2, 128.2,
127.7, 127.6, 127.5, 127.5, 127.3, 127.1, 126.8, 117.1, 100.2,
97.2, 86.2, 80.0, 77.8, 76.2, 74.9, 74.7, 73.8, 72.6, 71.6, 71.3,
71.2, 70.8, 70.7, 70.6, 70.5, 70.0, 69.7, 69.3, 63.2, 54.8, 37.9;
FABMS calcd for [C70H80O16SNa] 1231.5, found 1231.2.
Meth yl 2-O-[2′,3′,4′-Tr i-O-ben zyl-6′-O-(1′′-h yd r oxy-3,6-
d ioxa octyl)-D-ga la ctop yr a n osyl]-3-O-a llyl-4-O-ben zyl-6-
O-m eth a n esu lfon yl-r-D-m a n n op yr a n osid e (55). Disac-
charide 54 (708 mg, 0.58 mmol) was dissolved in 9:1 MeOH:
EtOAc (10 mL), and a catalytic amount of p-toluensulfonic acid
was added. The reaction mixture was stirred for 5 h. Tri-
ethylamine (200 µL) was added, solvents were evaporated, and
the residue was purified by chromatography (2:1 EtOAc-
pentane) to provide 55 (453 mg, 80%) as an oil: [R]D +71.4° (c
0.7, CHCl3); 1H NMR (360 MHz, CDCl3) δ 7.48-7.15 (m, 20H),
5.88 (ddd, 1H, J ) 17.2, 10.4, 5.7 Hz), 5.50 (d, 1H, J ) 3.9
Hz), 5.27 (ddd, 1H, J ) 17.2, 3.1, 1.6 Hz), 5.14 (ddd, 1H, J )
10.4, 3.1, 1.3 Hz), 4.96 (d, 1H, J ) 11.5 Hz), 4.95 (d, 1H, J )
11.7 Hz), 4.81 (d, 1H, J ) 12.2 Hz), 4.75 (d, 1H, J ) 12.2 Hz),
4.69 (d, 1H, J ) 11.5 Hz), 4.68 (d, 1H, J ) 1.9 Hz), 4.63 (d,
1H, J ) 10.9 Hz), 4.61 (d, 1H, J ) 11.5 Hz), 4.49 (dd, 1H, J )
11.8, 1.7 Hz), 4.37 (dd, 1H, J ) 11.8, 4.0 Hz), 4.27 (d, 1H, J )
11.0 Hz), 4.15 (dddd, 1H, J ) 12.6, 5.6, 1.6, 1.3 Hz), 4.10 (dd,
1H, J ) 2.4, 1.8 Hz), 4.08 (m,1H), 4.07 (dd, 1H, J ) 10.1, 3.8
Hz), 3.97 (d, 1H, J ) 2.0 Hz), 3.88 (t, 1H, J ) 5.5 Hz), 3.87
(dd, 1H, J ) 9.7, 9.6 Hz), 3.78 (dd, 1H, J ) 10.1, 2.0 Hz), 3.77
(dd, 1H, J ) 9.7, 2.4 Hz), 3.43-3.72 (m, 15H), 3.27 (s, 3H),
2.92 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 138.6, 138.5, 138.4,
138.0, 134.3, 128.2, 128.1, 128.1, 128.0, 127.5, 127.4, 127.4,
127.1, 126.9, 116.9, 100.0, 97.2, 79.8, 77.7, 76.1, 74.7, 73.6, 72.4,
74.2, 71.6, 71.5, 71.2, 71.1, 70.5, 70.3, 70.3, 70.2, 70.0, 69.9,
69.5, 69.2, 61.4, 54.7, 37.7. Anal. Calcd for C51H66O16
S
(967.14): C, 63.34; H, 6.88; S, 3.31. Found: C, 63.21; H, 6.84;
S, 3.44.
Ack n ow led gm en t. R. Alibe´s acknowledges postdoc-
toral fellowship support from the Generalitat de Cata-
lunya, Spain. The research was made possible by
Natural Science and Engineering Research Council of
Canada (NSERC) and Merck Frosst research grants to
D. R. Bundle.
Su p p or tin g In for m a tion Ava ila ble: 1H NMR spectra of
1
the target compounds 2-4 and a list of the H and 13C NMR
chemical shift assignments and homonuclear 3J coupling
constants (40 pages). This material is contained in libraries
on microfiche, immediately follows this article in the microfilm
version of the journal, and can be ordered from the ACS; see
any current masthead page for ordering information.
J O9806097