Assembly of a series of malarial glycosylphosphatidylinositol anchor oligosaccharides

Article abstract of DOI:10.1002/chem.200400934

We report an efficient and convergent synthesis of a series of oligosaccharides comprised of the malaria GPI glycan (2 a), a promising anti-malaria vaccine candidate currently in preclinical trials and several related oligosaccharide sequences (3-8) that

Full text of DOI:10.1002/chem.200400934

FULL PAPER
Assembly of a Series of Malarial Glycosylphosphatidylinositol Anchor
Oligosaccharides
Yong-Uk Kwon, Regina L. Soucy, Daniel A. Snyder, and Peter H. Seeberger*[a]
Abstract: We report an efficient and
convergent synthesis of a series of oli-
gosaccharides comprised of the malaria
GPI glycan (2a), a promising anti-ma-
laria vaccine candidate currently in
preclinical trials and several related oli-
gosaccharide sequences (3–8) that are
possible biosynthetic precursors of the
malarial GPI. A flexible synthetic strat-
egy is disclosed that relies on a late-
stage coupling between oligomanno-
sides of varying length and pseudo-dis-
accharide glycosyl acceptor 11 to readi-
ly access various malarial GPI struc-
tures. Phosphorylation was accomplish-
ed by mild and efficient H-phospho-
nate chemistry before the final
deprotection was carried out by using
sodium in ammonia. The direct connec-
tion of a thiol group via a phosphate
diester linkage to the inositol moiety
provides a handle for easy conjugation
of the GPI glycan to carrier proteins,
immobilization on carbohydrate micro-
arrays and photo-affinity labels identi-
fication. These synthetic oligosacchar-
ides will serve as molecular probes.
Keywords:
glycosylation
carbohydrates
malaria
·
·
·
oligosaccharides · vaccines
Introduction
form on the cell surface that constitutes the toxin responsi-
ble for morbidity and mortality by malaria.[3–9]
Forty percent of the worldꢀs population lives with the risk of
contracting malaria. While only about 1% of all malaria
cases are lethal, malaria continues to claim the lives of over
two million people annually. The spread of drug-resistant
parasites and insecticide-resistant mosquitoes renders malar-
ia as dangerous as ever.[1] Though more and more infectious
diseases are being controlled by the cost-effective and easily
administered means of vaccines, no viable vaccine candidate
has been developed for malaria.[2] Glycosylphosphatidylino-
sitol (GPI) anchors are a class of naturally occurring glycoli-
pids that link proteins and glycoproteins via their C-termi-
nus to cell membranes. The malarial parasite, Plasmodium
falciparum, expresses GPI in protein anchored and free
We have previously demonstrated that mice vaccinated
with a synthetic GPI glycan conjugated to a carrier protein,
produced anti-GPI antibodies and had a greatly improved
chance of survival upon infection with P. falciparum.[10] Be-
tween 60–75% of vaccinated mice, compared with 0–9%
sham-immunized mice, survived. The parasite levels ob-
served in the blood of the vaccine and control groups did
not differ significantly, thus indicating that the synthetic GPI
glycan conjugate serves as an anti-toxin vaccine.
Initial efforts focused on the solution phase synthesis of
malaria toxin 1a in order to confirm the structural assign-
ment made by Schofield based on the analysis of isolated
material (Figure 1). Conjugation of 1a to a carrier protein
produced the first generation vaccine candidate 1b. The as-
sembly of 1a was significantly accelerated by automated
solid phase synthesis of the GPI glycan.[11] Still, both routes
used to prepare GPI oligosaccharides relied on synthetic
paths that allowed no flexibility around the GPI glycan core.
In order to determine the minimum structural requirements
of GPI glycans to elicit a protective immune response, to
map the epitopes of human anti-malarial antibodies, and to
study the substrate specificity of GPI biosynthetic enzymes,
ready access to a series of GPI glycans is required.
[a] Dr. Y.-U. Kwon,# Dr. R. L. Soucy, D. A. Snyder,
Prof. Dr. P. H. Seeberger#
Department of Chemistry
Massachusetts Institute of Technology
Cambridge, MA 02139 (USA)
E-mail: seeberger@org.chem.ethz.ch
[#] New Address: Laboratory for Organic Chemistry, ETH Hçnggerberg
HCI F315Wolfgang-Pauli-Strasse 10, 8093 Zꢁrich (Switzerland)
Fax : (+41)1-633-1235
Many GPI structures have been synthesized by using vari-
ous chemical methodologies and protective group combina-
tions.[12–22] Structural studies on GPIs were the basis for sub-
Supporting information for this article is available on the WWW
1
under http://www.chemeurj.org/ or from the author: Selected H and
13C NMR spectra.
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DOI: 10.1002/chem.200400934
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saccharides that will serve as
molecular tools for studies into
the biosynthesis, antigenicity
and serology of GPIs. These
structures will be the basis for
the first detailed structure-ac-
tivity relationships between
GPI toxin and anti-malarial an-
tibodies and/or for mapping the
specificity of anti-malarial anti-
bodies (Figure 2).
Results and Discussion
Figure 1. Anti-toxin malaria vaccine candidates.
Retrosynthetic analysis: The
synthesis of a series of GPI oli-
gosaccharides differing in the
stantial synthetic work, resulting in total syntheses of the T.
brucei anchor,[12,13] rat-brain Thy-1 anchor,[14–16] a ceramide-
linked yeast anchor,[17] a GPI core structure lacking the
phosphoethanolamine,[18] non-lipidated Toxoplasma gondii
anchor,[19] the sperm CD52 anchor containing an acylated in-
ositol,[20] and a GPI structure containing an acylated inositol
ring as well as lipid moieties.[21,22]
In nature, the GPI toxin is anchored in the cell membrane
by a lipid portion connected to the inositol ring via a phos-
phate diester. On this basis, the second-generation malaria
GPI vaccine candidate 2a[23] was designed (Figure 1). Place-
ment of a thiohexanolphosphate group on the inositol
moiety provides a point for ready attachment to carrier pro-
teins. Here, we report the synthesis of a series of GPI oligo-
number of mannoses required us to adopt a synthetic strat-
egy relying on late-stage coupling and modification maneu-
vers. The retrosynthesis for 2a may serve as an example for
the overall approach. Fully protected oligosaccharide 9 will
be the target as it will allow for ready functionalization of
the oligosaccharide backbone to create the target molecule.
Key to our approach is the n+2 coupling between the man-
nose oligosaccharides such as 10 and glucosamine-inositol
pseudodisaccharide 11. For the creation of the oligomanno-
sides (e.g. 10), just three mannose monomers 12–14 would
be required (Figure 3). Installation of the phosphate groups
was to be effected by use of H-phosphonates. These phos-
phate ester synthons are very stable and can be purified and
stored, but upon activation are highly efficient phosphory-
Figure 2. Target GPI glycan oligosaccharides of different length.
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Anchor Oligosaccharides
FULL PAPER
Figure 3. Retrosynthetic analysis for the assembly of GPI oligosaccharides.
lating agents.[24] The removal of all protective groups at the
end of the synthesis was to be achieved by Birch reduction.
20, phosphorylation and deprotection protocol established
for 3, the fully protected trisaccharide 21 was prepared. All
benzyl ether and ester protective groups present in 21 were
readily cleaved under Birch conditions to furnish a mixture
of the desired trisaccharide 4 and the corresponding disul-
fide.
Before the synthesis of longer GPI sequences could be
contemplated, a series of oligomannosides to serve as glyco-
sylating agents in the convergent synthesis of the glycan
backbone had to be assembled (Scheme 3). Reaction of
mannose monomers 12 and 14[28] yielded dimannoside 22.
Removal of the anomeric allyl group and installation of the
Synthesis of GPI glycans of varying length: Disaccharide 3,
the shortest GPI glycan to be prepared, was readily accessi-
ble from known pseudo-disaccharide 11[13] (Scheme 1). Ben-
zylation of 11 to afford disaccharide 15 was followed by re-
moval of the allyl group with palladium(ii) chloride in wet
acetic acid to provide 16.[25] H-Phosphonate 17 was prepared
by phosphorylation of protected 6-mercapto-1-hexanol.[26]
Phosphorylation of 16 by activation of 17 with pivaloyl chlo-
ride was directly followed by oxidation of the H-phospho-
nate diester to the correspond-
ing phosphate diester 18 by
treatment with wet iodine. Oxi-
dation with iodine allowed for
selective oxidation of the H-
phosphonate without oxidation
of the thioether present in the
molecule.[27] Removal of all
protective groups in one step
by using sodium in ammonia af-
forded a mixture of the target
compound 3 that was accompa-
nied by the corresponding di-
sulfide.
Scheme 1. Synthesis of GPI disaccharide 3. a) BnBr, NaH, DMF, 99%; b) PdCl2, NaOAc, AcOH, H2O, 60%;
c) 1) 17, PivCl, pyridine; 2) I2, H2O, 97%; d) Na, NH3, CH3OH, THF, 70%.
Glycosylation of key inter-
mediate 11 with the known
mannose trichloroacetimidate
12[17] in the presence of
TMSOTf provided trisaccharide
19 in 90% yield (Scheme 2).
Following the deallylation to
Scheme 2. Synthesis of the GPI glycan trisaccharide 4. a) TMSOTf, CH2Cl2, 90%; b) PdCl2, NaOAc, AcOH,
produce trisaccharide alcohol H2O, 66%; c) 1) 17, PivCl, pyridine; 2) I2, H2O, 78%; d) Na, NH3, CH3OH, THF, 63%.
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P. H. Seeberger et al.
trichloroacetimidate leaving group fashioned disaccharide
building block 23. Selective removal of the acetate ester 22
in the presence of benzoate by treatment with hydrogen
chloride furnished disaccharide 24.[29] Glycosylation of 24
with differentially protected mannose 13[10,11] yielded triman-
noside 25 that was readily converted into glycosylating
agent 26. Alternatively, selective deprotection by exposure
to magnesium methoxide gave 27,[30] before mannosylation
by using differentially protected mannose 12 resulted in the
formation of tetrasaccharide 28. Deallylation and formation
of the glycosyl trichloroacetimidate furnished the tetrasac-
charide building block 29.
was carried using a two-step procedure: removal of the
esters by using sodium methoxide in methanol was followed
by Birch conditions to afford a mixture of the desired tetra-
saccharide 5 and the corresponding disulfide in 58% yield.
The synthesis of the two different pentasaccharide dele-
tion sequences 6 and 7 commenced with the deallylation of
31 by using palladium(ii) chloride in aqueous acetic acid. Al-
cohol 33 was phosphitylated by treatment with H-phospho-
nate 17 and pivaloyl chloride before oxidation with wet
iodine provided the phosphodiester 36 in 95% yield. The
TIPS group masking the primary C6 hydroxyl of the termi-
nal mannose of 36 was removed using Sc(OTf)3 in wet ace-
tonitrile at 508C to afford alcohol 38 in 76% yield.[31] To in-
troduce the second phosphate ester 38 was treated with H-
phosphonate 40[12] and pivaloyl chloride, again followed by
oxidation with wet iodine to furnish 41. The global depro-
tection of 38 and 41 was accomplished by the removal of the
ester groups using sodium methoxide in methanol and sub-
sequent Birch reaction to afford pentasaccharides 6 and 7 in
59% and 56% yield, respectively. In both cases the target
compounds were accompanied by the disulfide dimers.
Following the successful preparation of two pentasacchar-
ides, hexasaccharides 2a and 8 were the next synthetic tar-
gets. Deallylation of hexasaccharide 9 by palladium(ii) chlo-
ride in aqueous acetic acid furnished the alcohol 34 before
the previously established (see above) phosphitylation–oxi-
dation sequence yielded phosphate diester 37 in 96% yield.
The temporary TIPS group of 37 was removed by using Sc-
(OTf)3 in wet acetonitrile at 508C to furnish the alcohol 39
in 79% yield. Installation of the second phosphate diester
on 39 by treatment with H-phosphonate 40 and pivaloyl
With the oligomannoside building blocks (23, 26, and 29)
in hand, the assembly of the GPI glycan backbone was only
one step away. Coupling of these oligomannosides with dis-
accharide 11 afforded the corresponding tetra- (30), penta-
(31) and hexasaccharides (9) in excellent yield (Scheme 4).
Tetrasaccharide 32 was derived by deallylation of 30 with
palladium(ii) chloride in wet acetic acid, and was subse-
quently phosphitylated by the treatment of H-phosphonate
17 and pivaloyl chloride. Successive oxidation with wet
iodine afforded the fully protected tetrasaccharide 35. Birch
conditions were applied with the intent to remove all pro-
1
tective groups present in 35. The H NMR of the isolated
product revealed small peaks in the region between 7 and
8 ppm. These unexpected resonances did not indicate re-
maining benzyl groups, instead, more likely, the peaks origi-
nated from the partially remaining benzoate group. The
benzoate group may be transferred during the Birch reac-
tion to the amine that is obtained by reduction of the azide
on glucosamine. Therefore, the global deprotection of 35
Scheme 3. Synthesis of the oligomannoside building blocks 23, 26, and 29. a) TMSOTf, CH2Cl2, 97%; b) 1) PdCl2, NaOAc, AcOH, H2O; 2) Cl3CCN,
DBU, CH2Cl2 68% (two steps); c) HCl (AcCl, CH3OH), 91%; d) 13, TMSOTf, CH2Cl2, 93%; e) 1) PdCl2, NaOAc, AcOH, H2O; 2) Cl3CCN, DBU,
CH2Cl2 65% (two steps); f) Mg(OCH3)2, CH3OH, THF, 78%; g) 12, TMSOTf, CH2Cl2, 80%; h) 1) PdCl2, NaOAc, AcOH, H2O; 2) Cl3CCN, DBU,
CH2Cl2 62% (two steps).
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Anchor Oligosaccharides
FULL PAPER
Scheme 4. Synthesis of GPI oligosaccharides (5–8 and 2a). a) 11, TMSOTf, CH2Cl2, 82% for 30, 94% for 31, 73% for 9; b) PdCl2, NaOAc, AcOH, H2O,
58% for 32, 55% for 33, 57% for 34; c) 1) 17, PivCl, pyridine; 2) I2, H2O, 83% for 35, 95% for 36, 96% for 37; d) 1) NaOCH3, CH3OH, 608C; 2) Na,
NH3, CH3OH, THF, 58% (two steps); e) Sc(OTf)3, H2O, CH3CN, 76% for 38, 79% for 39; f) 1) NaOCH3, CH3OH, 608C; 2) Na, NH3, CH3OH, THF,
59% for 6, 61% for 8 (two steps); g) 1) 40, PivCl, pyridine; 2) I2, H2O, 62% for 41, 72% for 42; h) 1) NaOCH3, CH3OH, 608C; 2) Na, NH3, CH3OH,
THF, 56% for 7, 53% for 2a (two steps).
chloride followed by oxidation afforded 42 in 72% yield.
The protective groups of 39 and 42 were completely re-
moved by successive treatment with sodium methoxide in
methanol and Birch conditions to provide the two target
hexasaccharides 8 and 2a, respectively.
GPIs. Finally, the structures derived via the new synthetic
pathway disclosed here, will serve as useful substrates for
ELISA tests to detect anti-GPI antibodies in both naturally
immune and vaccinated individuals.
By developing a highly convergent and reliable synthetic
route to the assembly of GPI glycans based on the combina-
tion of mannosides with a glucosamine–inositol disaccharide
we established the platform for further biological investiga-
tions. Although the target compounds were accompanied by
the corresponding disulfide dimers, they can be readily re-
duced to thiol-functionalized GPIs by treatment with tris-
(carboxyethyl)phosphine hydrochloride (TCEP) before con-
jugation.[32] The new synthetic GPI glycan 2a will be conju-
gated to carrier proteins (2b) and will await testing as anti-
toxin malaria vaccine candidate. The related shorter GPI
oligosaccharides 3–8 are readily converted into molecular
probes carrying biotin or fluorescent groups by alkylation of
the terminal thiol group. Addition of these thiols to appro-
priately treated surfaces will provide access to GPI microar-
rays that will be used in epitope mapping and other biologi-
cal studies including investigations into the biosynthesis of
Conclusion
We have reported the efficient synthesis of a malaria GPI
glycan and a series of related oligosaccharide sequences.
Our flexible synthetic strategy, involving late-stage coupling/
modification, allows for easy access to various malarial GPI
structures ready for biological studies. Direct incorporation
of thiol group into inositol moiety of GPI structures pro-
vides easy conjugation of GPI glycan to carrier proteins,
convenient screening on carbohydrate chips and the poten-
tial as photo-affinity labels for receptor/protein identifica-
tion. The molecules derived during the study reported here,
will find use as anti-toxin malaria vaccine candidates, molec-
ular probes for epitope mapping of anti-malarial antibodies
and for other biological studies, to reveal the minimal struc-
tural requirements that convey protection from malaria.
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P. H. Seeberger et al.
and brine, dried, filtered, and concentrated. Chromatography (EtOAc/
hexane 1:9 ! 1:3) of the crude product afforded 6-(S-benzyl)thiohexa-
nol. A solution of imidazole (15 g, 220 mmol), triethylamine (38 mL,
273 mmol) and phosphorus trichloride (6.4 mL, 73.3 mmol) in CH2Cl2
(700 mL) was stirred for 15 min at 08C. To the resulting mixture was
added 6-(S-benzyl)thiohexanol in CH2Cl2 (50 mL) dropwise for 1 h at
08C. After being stirred for 1 h at 08C, water (30 mL) was added to
quench the reaction. The organic layer was washed with 1n HCl, dried,
filtered, and concentrated. The crude product was purified by chromatog-
raphy (EtOAc/isopropanol/water 5:4:1 with 1% AcOH) to give 6-(S-ben-
zyl)thiohexyl H-phosphonate (17) (3.8 g, 72% over two steps). Rf =0.38
(CH3OH/CH2Cl2 1:20); 1H NMR (CDCl3): d=1.33–1.44 (m, 4H), 1.54–
1.61 (m, 2H), 1.65–1.72 (m, 2H), 2.41 (t, J=7.2 Hz, 2H), 3.70 (s, 2H),
3.97–4.06 (m, 2H), 7.21–7.39 (m, 5H); 13C NMR (CDCl3): d=28.7, 29.1,
29.2, 31.3, 31.4, 32.4, 62.7, 126.8, 128.3, 128.7, 138.5; 31P NMR (CDCl3):
d=7.47; HRMS (ESI): m/z: calcd for C13H20O3PS: 287.0871; found
287.0879 [M]ꢀ.
Experimental Section
General methods: All nonhydrolytic reactions were carried out in oven-
dried glassware under dry argon or nitrogen atmosphere. All commercial
reagents were used as obtained without further purification. Analytical
thin-layer chromatography was performed on Merck silica gel 60 F254
glass plates (0.25 mm). Compounds were visualized by dipping the plates
in a cerium sulphate/ammonium molybdate solution followed by heating.
Flash chromatography was performed using forced flow of the indicated
solvent on silica gel (230–400 mesh). NMR spectra were recorded on a
Bruker Avance 400, Bruker Avance 500, or Varian Mercury-300 spec-
1
trometer; see Supporting Information for selected H and 13C NMR spec-
tra. IR spectra were obtained on a Perkin-Elmer 1600 series FT-IR spec-
trometer. Mass spectra (ESI or MALDI-TOF) were determined on a
Bruker Daltonics Apex 3 Telsa FT Spectrometer, an Ionspec Ultima 4.7
Telsa FTICR Spectrometer, or a Bruker FTMS 4.7 Telsa BioAPEX II
Spectrometer. Optical rotations were measured with a Perkin-Elmer 241
polarimeter.
Triethylammonium (2-azido-3,4,6-tri-O-benzyl-2-deoxy-a-d-glucopyrano-
syl)-(1!6)-2,3,4,5-tetra-O-benzyl-1-O-(6-(S-benzyl)thiohexyl
phospho-
Preparation of compound 3
no)-d-myo-inositol (18): A mixture of compound 16 (62 mg, 0.062 mmol)
and H-phosphonate 17 (179 mg, 0.62 mmol) was coevaporated with pyri-
dine (3ꢃ3 mL) and dried in vacuo. To the solution of the residue in pyri-
dine (2 mL) was added pivaloyl chloride (150 mL, 1.22 mmol) at room
temperature. After 3 h, water (0.2 mL) and iodine (170 mg, 0.67 mmol)
were added. After 1 h, the mixture was diluted with CH2Cl2 and washed
with 1m Na2S2O3 and water. The organic phase was dried over MgSO4,
filtered and concentrated. Chromatography (CH3OH/CH2Cl2 gradient
with 1% Et3N) afforded phosphodiester 18 (83 mg, 97%). Rf =0.3
(CH3OH/CH2Cl2 1:10); [a]2D5 =+58.2 (c=1.77 in CHCl3); 1H NMR
(CDCl3): d=1.21–1.45 (m, 19H), 2.39 (t, J=7.4 Hz, 2H), 3.03 (q, J=
7.1 Hz, 6H), 3.24 (dd, J=3.7, 10.0 Hz, 1H), 3.38–3.53 (m, 3H), 3.60 (dd,
J=2.0, 9.8 Hz, 1H), 3.68–3.78 (m, 3H), 3.93–4.18 (m, 4H), 4.30–4.38 (m,
3H), 4.47 (d, J=11.0 Hz, 1H), 4.57 (d, J=12.0 Hz, 1H), 4.64 (d, J=
11.6 Hz, 1H), 4.66–5.03 (m, 10H), 5.92 (d, J=3.6 Hz, 1H), 7.02–7.58 (m,
40H), 12.3 (s, 1H); 13C NMR (CDCl3): d=8.9, 25.8, 27.7, 29.1, 29.6, 31.3,
31.7, 36.6, 45.9, 63.6, 66.2, 68.5, 70.4, 72.6, 73.7, 74.6, 74.7, 75.1, 75.2, 75.6,
76.1, 76.5, 77.0, 77.9, 78.0, 78.8, 80.3, 81.4, 82.0, 82.3, 97.1, 127.5, 127.9,
128.1, 128.3, 128.4, 128.5, 128.6, 128.7, 128.8, 129.2, 138.5, 138.6, 138.9,
139.0, 139.1, 140.3; 31P NMR (CDCl3): d=0.11; IR (film): n˜ =3030, 2931,
(2-Azido-3,4,6-tri-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-1-O-
allyl-2,3,4,5-tetra-O-benzyl-d-myo-inositol (15): Benzyl bromide (60 mL,
0.5 mmol) was added at 08C to a mixture of compound 11[13] (118 mg,
0.12 mmol), tetrabutylammonium iodide (5 mg, 0.013 mmol) and NaH
(60%, 30 mg, 0.75 mmol) in DMF (3 mL). The mixture was slowly
warmed up to room temperature. After 6 h, CH3OH was added to
quench the reaction, and the solvents were removed. Chromatography
(EtOAc/hexane 1:12
!
1:4) of the residue afforded compound 15
(128 mg, 99%) as a syrup. Rf =0.42 (EtOAc/hexane 1:4); [a]2D5 =+54.8
(c=4.25 in CHCl3); 1H NMR (CDCl3): d=3.14 (dd, J=2.0, 8.3 Hz, 1H),
3.24 (dd, J=1.6, 11.0 Hz, 1H), 3.35 (dd, J=3.8, 10.3 Hz, 1H), 3.40–3.49
(m, 3H), 3.77 (t, J=9.5 Hz, 1H), 3.99 (dd, J=9.1, 10.2 Hz, 1H), 4.04–
4.07 (m, 4H), 4.19 (t, J=9.5 Hz, 1H), 4.25–4.32 (m, 2H), 4.42 (d, J=
11.0 Hz, 1H), 4.58 (d, J=12.0 Hz, 1H), 4.65–4.77 (m, 4H), 4.85–4.93 (m,
5H), 5.03 (d, J=10.6 Hz, 1H), 5.08 (d, J=10.8 Hz, 1H), 5.24 (dd, J=1.4,
10.5 Hz, 1H), 5.33 (dd, J=1.6, 17.2 Hz, 1H), 5.78 (d, J=3.8 Hz, 1H),
5.94–6.03 (m, 1H), 7.10–7.45 (m, 35H); 13C NMR (CDCl3): d=63.9, 68.0,
70.4, 71.3, 73.2, 73.3, 74.5, 75.1, 75.7, 75.9, 76.1, 76.2, 77.7, 80.7, 81.3, 81.8,
82.3, 82.4, 98.1, 117.4, 127.7, 127.9, 128.0, 128.1, 128.2, 128.3, 128.4, 128.5,
128.6, 128.7, 128.8, 128.9, 134.7, 138.4, 138.5, 138.6, 138.7, 138.9, 139.0,
2107, 1454, 1360, 1126, 1052 cmꢀ1
; HRMS (ESI): m/z: calcd for
139.3; IR (film): n˜ =3030, 2866, 2105, 1454, 1359, 1127, 1053 cmꢀ1
;
C80H98N4O113PS: 1385.6521; found 1385.6479 [M+H]+.
HRMS (ESI): m/z: calcd for C64H67N3O10Na 1060.4719; found 1060.4700
[M+Na]+.
(2-Amino-2-deoxy-a-d-glucopyranosyl)-(1!6)-1-O-(6-thiohexyl phospho-
no)-d-myo-inositol (3): Ammonia (~20 mL) was condensed in a flame-
dried three-necked flask at ꢀ788C. Sodium metal was added portionwise
until the solution was dark blue. Phosphodiester 18 (48 mg, 0.035 mmol)
in THF (7 mL) was added via cannula, followed by CH3OH (0.1 mL).
The resultant dark blue solution was stirred at ꢀ788C for 30 min. Follow-
ing disappearance of the blue color, EtOH (2 mL) and AcOH (~0.5 mL)
were added and ammonia was blown off with a stream of Ar. Chroma-
tography of the crude mixture on Sephadex G-25 (EtOH/H2O 1:1), fol-
lowed by dialysis and lyophilization afforded a mixture of the target com-
pound 3 and the corresponding disulfide (13 mg, 70%). 1H NMR (D2O):
d=1.35–1.83 (m, 10H), 2.86 (t, J=7.2 Hz, 2H), 3.36–3.48 (m, 1H), 3.53
(t, J=9.3 Hz, 1H), 3.60–3.65 (m, 2H), 3.78 (t, J=9.7 Hz, 1H), 3.90–4.04
(m, 4H), 4.19 (td, J=3.5, 10.1 Hz, 1H), 4.26–4.30 (m, 2H), 5.61 (d, J=
3.7 Hz, 1H); 13C NMR (D2O): d=24.8, 27.5, 28.5, 30.0, 38.5, 54.7, 60.4,
66.7, 68.8, 70.8, 71.6, 72.4, 72.5, 73.2, 76.4, 78.0, 97.5; 31P NMR (D2O): d=
1.49; HRMS (ESI): m/z: calcd for C36H70N2O26P2S2Na: 1095.3026; found
1095.3024 [M+H]+.
(2-Azido-3,4,6-tri-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-2,3,4,5-
tetra-O-benzyl-d-myo-inositol (16): Compound 15 (117 mg, 0.11 mmol)
was dissolved in AcOH (3 mL). Water (0.15 mL) was added, followed by
NaOAc (185 mg, 2.25 mmol) and PdCl2 (196 mg, 1.11 mmol), and the
mixture was stirred for 24 h at room temperature. The reaction mixture
was diluted with EtOAc and washed with water, saturated aqueous
NaHCO3, and brine. The organic phase was dried over MgSO4, filtered,
concentrated and purified by chromatography (EtOAc/hexane 1:6 ! 1:4)
to give compound 16 (68 mg, 60%). Rf =0.2 (EtOAc/hexane 1:4); [a]D25
=
+52.0 (c=2.90 in CHCl3); 1H NMR (CDCl3): d=3.10 (dd, J=1.5,
11.0 Hz, 1H), 3.26–3.30 (m, 2H), 3.46 (t, J=13.3 Hz, 1H), 3.52–3.58 (m,
2H), 3.68 (ddd, J=2.5, 6.2, 9.1 Hz, 1H), 3.79 (t, J=9.9 Hz, 1H), 4.00–
4.08 (m, 4H), 4.14–4.21 (m, 2H), 4.45 (d, J=10.9 Hz, 1H), 4.53 (d, J=
12.0 Hz, 1H), 4.68–5.11 (m, 12H), 5.51 (d, J=3.6 Hz, 1H), 7.21–7.45 (m,
35H); 13C NMR (CDCl3): d=64.5, 67.8, 71.3, 73.3, 73.8, 74.0, 75.2, 75.7,
75.9, 76.3, 77.4, 78.5, 80.9, 81.2, 81.4, 81.6, 82.4, 98.8, 127.9, 128.1, 128.2,
128.4, 128.5, 128.7, 128.8, 128.9, 138.2, 138.3, 138.5, 138.7, 138.8, 138.9,
139.0; IR (film): n˜ =3468, 3030, 2868, 2111, 1454, 1361, 1128, 1049 cmꢀ1
;
Preparation of compound 4
HRMS (ESI): m/z: calcd for C61H63N3O10Na: 1020.4406; found 1020.4429
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-
di-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-1-O-allyl-2,3,4,5-tetra-
O-benzyl-d-myo-inositol (19): Disaccharide 11[13] (200 mg, 0.21 mmol)
and mannose donor 12[17] (150 mg, 0.24 mmol) were coevaporated with
toluene (3ꢃ3 mL), dried in vacuo and dissolved in CH2Cl2 (5 mL). The
solution was cooled to 08C, followed by the addition of TMSOTf (7 mL,
38 mmol), and stirred for 2 h. The reaction was quenched by the addition
of Et3N (0.1 mL) and the reaction mixture was concentrated. The crude
[M+Na]+.
6-(S-Benzyl)thiohexyl H-phosphonate (17): Sodium methoxide (25wt%,
4.2 mL, 18.4 mmol) and benzyl chloride (2.12 mL, 18.3 mmol) were
added dropwise at 08C to a solution of 6-mercapto-1-hexanol (2.5 mL,
18.3 mmol) in EtOH (40 mL). The mixture was heated at reflux for 1 h,
cooled, and concentrated. The residue was thoroughly extracted with
CH2Cl2. The organic layer was washed with saturated aqueous NaHCO3
2498
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
Chem. Eur. J. 2005, 11, 2493 – 2504

Anchor Oligosaccharides
FULL PAPER
product was purified by chromatography (EtOAc/toluene 1:30 ! 1:20)
affording trisaccharide 19 (270 mg, 90%). Rf =0.36 (EtOAc/toluene
1:10); [a]2D5 =+59.4 (c=0.95 in CHCl3); 1H NMR (CDCl3): d=1.90 (s,
3H), 3.21 (d, J=10.7 Hz, 1H), 3.27–3.34 (m, 3H), 3.39–3.54 (m, 4H),
3.60 (dd, J=2.8, 10.7 Hz, 1H), 3.79 (dd, J=3.2, 9.4 Hz, 1H), 3.89–4.07
(m, 7H), 4.16 (t, J=9.5 Hz, 1H), 4.22–4.47 (m, 6H), 4.54–5.06 (m, 12H),
5.21 (dd, J=1.4, 10.5 Hz, 1H), 5.30 (dd, J=1.4, 16.9 Hz, 1H), 5.43 (d, J=
1.4 Hz, 1H), 5.49 (dd, J=1.9, 3.1 Hz, 1H), 5.76 (d, J=3.7 Hz, 1H), 5.91–
6.01 (m, 1H), 7.01–7.40 (m, 45H); 13C NMR (CDCl3): d=21.4, 63.8, 68.6,
68.7, 69.1, 70.0, 71.2, 72.2, 72.6, 73.1, 73.2, 73.6, 73.8, 74.1, 74.5, 74.6, 74.9,
75.3, 75.6, 76.0, 76.2, 77.7, 78.7, 81.0, 81.3, 81.6, 82.2, 82.4, 98.1, 99.6,
117.5, 127.4, 127.8, 128.0, 128.1, 128.3, 128.4, 128.5, 128.6, 128.7, 128.8,
128.9, 134.6, 138.1, 138.4, 138.6, 138.7, 138.8, 138.9, 139.2, 170.5; IR
Phosphodiester 21 (48 mg, 0.027 mmol) in THF (8 mL) was added via
cannula, followed by CH3OH (0.12 mL). The resultant dark blue solution
was stirred at ꢀ788C for 30 min. Following disappearance of the blue
color, EtOH (2 mL) and AcOH (~0.5 mL) were added and ammonia was
blown off with a stream of Ar. Chromatography of the crude mixture on
Sephadex G-25 (EtOH/H2O 1:1), followed by dialysis and lyophilization
afforded a mixture of the target compound 4 and the corresponding di-
sulfide (12 mg, 63%). 1H NMR (D2O): d=1.34–1.83 (m, 10H), 2.86 (t,
J=7.2 Hz, 2H), 3.45 (dd, J=3.6, 10.0 Hz, 1H), 3.50 (t, J=9.3 Hz, 1H),
3.62–4.30 (m, 16H), 5.36 (s, 1H), 5.62 (d, J=3.7 Hz, 1H); 13C NMR
(D2O): d=24.8, 27.4, 28.5, 30.0, 38.4, 54.7, 60.4, 61.1, 66.8, 68.9, 70.5, 70.6,
70.9, 71.3, 71.6, 72.5, 73.3, 74.0, 76.2, 76.3, 78.3, 101.8; 31P NMR (D2O):
d=1.53; HRMS (ESI): m/z: calcd for C48H91N2O36P2S2: 1397.4263; found
1397.4284 [M+H]+.
(film): n˜ =3030, 2867, 2105, 1741, 1454, 1363, 1236, 1101, 1050 cmꢀ1
;
HRMS (ESI): m/z: calcd for C86H91N3O16Na: 1444.6292; found 1444.6333
[M+Na]+.
Preparation of compounds 5–8 and 2a
Allyl
(2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-2-O-
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-
di-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-2,3,4,5-tetra-O-benzyl-
d-myo-inositol (20): Compound 19 (110 mg, 0.077 mmol) was dissolved in
AcOH (3 mL). Water (0.15 mL) was added, followed by NaOAc (128 mg,
1.56 mmol) and PdCl2 (140 mg, 0.79 mmol), and the mixture was stirred
for 24 h at room temperature. The reaction mixture was diluted with
EtOAc and washed with water, saturated aqueous NaHCO3, and brine.
The organic phase was dried over MgSO4, filtered, concentrated and pu-
rified by chromatography (EtOAc/toluene 1:20 ! 1:10) to give com-
pound 20 (70 mg, 66%). Rf =0.17 (EtOAc/toluene 1:10); [a]2D5 =+57.1
(c=2.75 in CHCl3); 1H NMR (CDCl3): d=2.03 (s, 3H), 3.10 (d, J=
6.8 Hz, 1H), 3.25 (d, J=11.1 Hz, 1H), 3.34–3.72 (m, 8H), 3.86 (dd, J=
2.8, 9.4 Hz, 1H), 3.92–4.06 (m, 6H), 4.14 (t, J=9.4 Hz, 1H), 4.24–5.08
(m, 19H), 5.44 (s, 1H), 5.53–5.55 (m, 2H), 7.21–7.43 (m, 45H); 13C NMR
(CDCl3): d = 21.4, 64.7, 68.7, 69.1, 70.9, 72.2, 72.7, 73.4, 73.6, 73.8, 73.9,
74.2, 75.0, 75.1, 75.3, 75.4, 75.5, 76.3, 77.6, 78.7, 80.7, 81.3, 81.4, 81.6, 82.3,
98.5, 99.6, 127.6, 127.8, 128.2, 128.3, 128.4, 128.5, 128.6, 128.7, 128.8,
128.9, 137.9, 138.4, 138.5, 138.6, 138.8, 138.9, 139.0, 139.2, 170.5; IR
benzoyl-3,4-di-O-benzyl-a-d-mannopyranoside (22): Trichloroacetimidate
12[17] (4.3 g, 6.7 mmol) and allyl gylcoside 14[28] (2.3 g, 4.6 mmol) were co-
evaporated with toluene (3ꢃ3 mL), dried in vacuo and dissolved in
CH2Cl2 (45 mL). The solution was cooled to 08C, followed by the addi-
tion of TMSOTf (53 mL, 0.28 mmol), and stirred for 2 h. The reaction
was quenched by the addition of Et3N (1 mL) and the reaction mixture
was concentrated. The crude product was purified by chromatography
(EtOAc/hexane 1:6 ! 1:4) affording disaccharide 22 (4.3 g, 97%). Rf =
0.5 (EtOAc/hexane 1:2); [a]2D5 =+33.4 (c=3.10 in CHCl3); 1H NMR
(CDCl3): d=2.18 (s, 3H), 3.61 (dd, J=1.5, 10.6 Hz, 1H), 3.71 (dd, J=3.7,
10.8 Hz, 1H), 3.76–3.83 (m, 2H), 3.88–4.04 (m, 6H), 4.12–4.21 (m, 2H),
4.42–4.50 (m, 4H), 4.55–4.72 (m, 3H), 4.82–4.91 (m, 3H), 4.98 (d, J=
1.8 Hz, 1H), 5.03 (d, J=2.1 Hz, 1H), 5.18–5.23 (m, 1H), 5.27–5.33 (m,
1H), 5.54 (dd, J=1.8, 3.0 Hz, 1H), 5.67 (dd, J=1.8, 3.0 Hz, 1H), 5.83–
5.96 (m, 1H), 7.11- 7.55 (m, 28H), 8.10–8.14 (m, 2H); 13C NMR (CDCl3):
d=21.3, 66.2, 68.2, 68.4, 68.7, 69.0, 70.8, 71.6, 71.7, 73.4, 74.2, 74.3, 75.1,
75.2, 77.9, 78.6, 96.8, 97.9, 118.1, 127.4, 127.5, 127.6, 127.7, 128.0, 128.1,
128.2, 128.3, 128.4, 128.5, 129.8, 129.9, 133.2, 137.6, 137.8, 138.1, 138.2,
138.4, 165.6, 170.2; IR (film): n˜ =3031, 2942, 2865, 1731, 1726, 1451, 1268,
(film): n˜ =3470, 3030, 2867, 2108, 1742, 1454, 1363, 1235, 1101, 1048 cmꢀ1
;
1237, 1112, 1059 cmꢀ1
;
HRMS (MALDI-TOF): m/z: calcd for
HRMS (ESI): m/z: calcd for C83H87N3O16Na: 1404.5979; found 1404.5997
[M+Na]+.
C59H62O13Na: 1001.4082; found 1001.4065 [M+Na]+.
Triethylammonium (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-
(1!4)-(2-azido-3,6-di-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-
2,3,4,5-tetra-O-benzyl-1-O-(6-(S-benzyl)thiohexyl phosphono)-d-myo-in-
ositol (21): A mixture of compound 20 (89 mg, 0.089 mmol) and H-phos-
phonate 17 (186 mg, 0.64 mmol) was coevaporated with pyridine (3ꢃ
3 mL) and dried in vacuo. To the solution of the residue in pyridine
(1.5 mL) was added pivaloyl chloride (120 mL, 0.97 mmol) at room tem-
perature. After 3 h, water (0.18 mL) and iodine (180 mg, 0.71 mmol)
were added. After 1 h, the mixture was diluted with CH2Cl2 and washed
with 1m Na2S2O3 and water. The organic phase was dried over MgSO4,
filtered and concentrated. Chromatography (CH3OH/CH2Cl2 gradient
with 1% Et3N) afforded phosphodiester 21 (89 mg, 78%). Rf =0.35
(CH3OH/CH2Cl2 1:10); [a]2D5 =+69.0 (c=2.10 in CHCl3); 1H NMR
(CDCl3): d=1.21–1.64 (m, 19H), 2.02 (s, 3H), 2.40 (t, J=7.4 Hz, 2H),
2.92 (q, J=7.3 Hz, 6H), 3.19 (dd, J=3.8, 9.7 Hz, 1H), 3.37–3.70 (m, 8H),
3.76 (dd, J=3.3, 9.4 Hz, 1H), 3.88–4.04 (m, 4H), 4.13–4.20 (m, 2H),
4.26–4.49 (m, 7H), 4.58–4.62 (m, 2H), 4.67 (d, J=11.6 Hz, 1H), 4.73 (d,
J=10.5 Hz, 1H), 4.79–5.03 (m, 9H), 5.08 (d, J=12.0 Hz, 1H), 5.41 (s,
1H), 5.45 (dd, J=1.7, 4.8 Hz, 1H), 5.99 (d, J=3.7 Hz, 1H), 7.22–7.59 (m,
50H); 13C NMR (CDCl3): d=8.9, 21.4, 25.8, 29.1, 29.6, 31.3, 31.7, 36.6,
46.0, 63.5, 68.8, 69.0, 69.2, 69.9, 72.2, 72.6, 73.5, 73.8, 74.2, 75.1, 75.3, 75.4,
76.1, 77.1, 77.6, 77.7, 78.7, 80.6, 81.4, 82.0, 82.3, 97.0, 99.8, 127.3, 127.6,
127.8, 127.9, 128.0, 128.1, 128.3, 128.4, 128.6, 128.7, 128.9, 129.2, 138.2,
138.4, 138.7, 139.0, 139.1, 139.3, 140.3, 170.4; 31P NMR (CDCl3): d=0.26;
IR (film): n˜ =3030, 2929, 2862, 2109, 1744, 1454, 1364, 1235, 1099,
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-2-O-benzo-
yl-3,4-di-O-benzyl-a-d-mannopyranosyl trichloroacetimidate (23): Com-
pound 22 (150 mg, 0.15 mmol) was dissolved in AcOH (3 mL). Water
(0.15 mL) was added, followed by NaOAc (180 mg, 2.20 mmol) and
PdCl2 (190 mg, 1.07 mmol), and the mixture was stirred for 24 h at room
temperature. The reaction mixture was diluted with EtOAc and washed
with water, saturated aqueous NaHCO3, and brine. The organic phase
was dried over MgSO4, filtered, concentrated and purified by chromatog-
raphy (EtOAc/hexane 1:4 ! 1:2) to give a lactol. This lactol was dis-
solved in CH2Cl2 (3 mL), and trichloroacetonitrile (0.75 mL) and DBU
(5 mL) were added at 08C. The mixture was stirred for 1.5 h and concen-
trated. Chromatography (EtOAc/hexane 1:4) gave compound 23 (113 mg,
68% from 22). Rf =0.50 (EtOAc/hexane 1:2); [a]2D5 =+41.7 (c=2.98 in
CHCl3); 1H NMR (CDCl3): d=2.20 (s, 3H), 3.63 (dd, J=1.5, 10.8 Hz,
1H), 3.76 (dd, J=3.9, 10.8 Hz, 1H), 3.84–4.09 (m, 7H), 4.19 (dd, J=3.2,
9.0 Hz, 1H), 4.45–4.53 (m, 5H), 4.63–4.73 (m, 3H), 4.86–4.93 (m, 3H),
5.01 (d, J=1.6 Hz, 1H), 5.53 (dd, J=2.0, 2.7 Hz, 1H), 5.82 (dd, J=2.1,
3.0 Hz, 1H), 6.39 (d, J=1.8 Hz, 1H), 7.16–8.20 (m, 30H), 8.75 (s, 1H);
13C NMR (CDCl3): d=21.6, 66.2, 68.1, 68.7, 69.1, 71.9, 72.0, 72.3, 73.7,
73.9, 74.5, 75.5, 75.8, 78.2, 78.4, 91.2, 95.6, 98.2, 128.0, 128.2, 128.3, 128.5,
128.6, 128.7, 128.8, 128.9, 129.1, 129.9, 130.4, 134.0, 137.8, 138.2, 138.4,
138.6, 139.0, 160.1, 165.9, 170.8; IR (film): n˜ =3334, 3031, 2931, 1730,
1675, 1453, 1366, 1263, 1237, 1096, 1043 cmꢀ1; HRMS (ESI): m/z: calcd
for C58H58Cl3NO13Na: 1104.2866; found 1104.2830 [M+Na]+.
Allyl (3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-2-O-benzoyl-3,4-
di-O-benzyl-a-d-mannopyranoside (24): Disaccharide 22 (1.68 g,
1.72 mmol) was dissolved in CH2Cl2 (5 mL) and CH3OH (60 mL). To the
reaction mixture was added acetyl choride (0.5 mL, 7.0 mmol) at 08C.
After being stirred at room temperature for 32 h, Et3N (1 mL) was added
and the reaction mixture was concentrated. The product, 24 (1.46 g,
91%) was isolated by flash column chromatography (EtOAc/hexane 1:4
1050 cmꢀ1
; HRMS (ESI): m/z: calcd for C96H105N3O19PS: 1666.6806;
found 1666.6795 [M]ꢀ.
(a-d-Mannopyranosyl)-(1!4)-(2-amino-2-deoxy-a-d-glucopyranosyl)-
(1!6)-1-O-(6-thiohexyl phosphono)-d-myo-inositol (4): Ammonia
(~20 mL) was condensed in a flame-dried three-necked flask at ꢀ788C.
Sodium metal was added portionwise until the solution was dark blue.
Chem. Eur. J. 2005, 11, 2493 – 2504
www.chemeurj.org
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2499

P. H. Seeberger et al.
! 1:2) as an oil. Rf =0.25 (EtOAc/hexane 1:2); [a]2D5 =+25.9 (c=1.00 in
CH2Cl2); 1H NMR (CDCl3): d=1.68 (brs, 1H), 3.61–3.71 (m, 2H), 3.82–
4.02 (m, 8H), 4.46–4.69 (m, 7H), 4.15 (m, 3H), 4.83 (d, J=10.8 Hz, 2H),
4.90 (d, J=10.9 Hz, 1H), 4.97 (s, 1H), 5.16 (s, 1H), 5.20–5.31 (dd, J=
17.2, 10.4 Hz, 2H), 5.65 (m, 1H), 5.84–5.90 (m, 1H), 7.16 (m, 2H), 7.27
(m, 23H), 7.43 (m, 2H), 8.09 (d, J=8.1 Hz, 2H); 13C NMR (CDCl3): d=
66.0, 68.4, 68.6, 68.9, 69.2, 71.4, 71.5, 71.8, 72.1, 73.6, 74.4, 74.5, 75.3, 75.5,
78.7, 80.1, 97.0, 99.6, 118.4, 127.8, 127.9, 128.0, 128.1, 128.2, 128.4, 128.5,
128.6, 128.7, 128.8, 130.1, 130.2, 133.5, 133.6, 138.0, 138.2, 138.4, 138.5,
138.6, 165.9; IR (film): n˜ =3437, 3031, 2924, 1724, 1602, 1496, 1453, 1269,
1117, 1059 cmꢀ1; HRMS (ESI): m/z: calcd for C57H64NO12: 954.4423;
found 954.4397 [M+NH4]+.
was isolated by chromatography (EtOAc/hexane 1:7 ! 1:4) as an oil.
Rf =0.50 (EtOAc/hexane 1:2); [a]2D5 =+18.3 (c=1.00 in CH2Cl2);
1H NMR (CDCl3): d=1.08 (s, 18H), 2.34 (d, J=3.1 Hz, 1H), 3.60 (d, J=
9.9 Hz, 1H), 3.68–3.71 (dd, J=4.1, 4.3 Hz, 1H), 3.79–4.02 (m, 13H),
4.14–4.19 (m, 3H), 4.24 (t, J=2.1, 2.0 Hz 1H), 4.43–4.59 (m, 9H), 4.66–
4.73 (m, 3H), 5.66 (m, 1H), 5.84–5.92 (m, 1H), 7.15–7.43 (m, 37H), 8.09
(d, J=7.1 Hz, 2H); 13C NMR (CDCl3): d=12.2, 12.5, 18.2, 18.3, 63.1,
64.9, 66.1, 66.5, 68.2, 68.8, 69.2, 70.9, 71.8, 72.1, 72.2, 72.3, 73.3, 73.4, 74.2,
74.4, 74.8, 75.2, 75.3, 78.9, 80.1, 96.8, 99.2, 100.6, 118.4, 124.6, 127.5, 127.6,
127.7, 127.8, 127.9, 128.0, 128.1, 128.4, 128.5, 128.6, 128.7, 130.0, 130.1,
133.4, 138.0, 138.2, 138.3, 138.7, 138.8, 165.9; IR (film): n˜ =3413, 2940,
2865, 1725, 1453, 1363, 1269, 1114, 1050, 737, 697 cmꢀ1; HRMS (ESI):
m/z: calcd for C86H106NO17Si: 1452.7225; found 1452.7236 [M+NH4]+.
Allyl (2-O-acetyl-3,4-di-O-benzyl-6-O-triisopropylsilyl-a-d-mannopyrano-
syl)-(1!2)-(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-2-O-benzoyl-
3,4-di-O-benzyl-a-d-mannopyranoside (25): Dissacharide acceptor 24
(0.52 g, 0.59 mmol) and mannose donor 13[10, 11] (0.53 g, 0.75 mmol) were
coevaporated with toluene (3ꢃ3 mL), dried in vacuo and dissolved in
CH2Cl2 (3 mL). The solution was cooled to 08C, followed by addition of
TMSOTf (7.5 mL, 40 mmol), and stirred for 2 h. The reaction was
quenched by addition of Et3N (0.5 mL) and the reaction mixture was
concentrated. The crude product was purified by chromatography
(EtOAc/hexane 1:10 ! 1:7) affording trisaccharide 25 (0.81 g, 93%).
Rf =0.56 (EtOAc/hexane 1:2); [a]2D5 =+13.8 (c=1.00 in CH2Cl2);
1H NMR (CDCl3): d=1.06 (s, 18H), 2.09 (s, 3H), 3.55–4.18 (m, 19H),
4.40 (s, 1H), 4.43 (d, J=2 Hz, 1H), 4.49–4.67 (m, 8H), 4.77–4.97 (m,
6H), 5.17 (d, J=1.3 Hz, 1H), 5.19 (d, J=1.1 1H), 5.28 (dd, J=17.2, 1.41,
1H), 5.50 (m, 1H), 5.64 (m, 1H), 5.82–5.90 (m, 1H), 7.14 (m, 3H), 7.20–
7.45 (m, 35H), 7.47 (m, 1H), 8.07 (d, J=7.1 Hz, 2H); 13C NMR (CDCl3):
d=12.5, 18.2, 21.2, 62.9, 66.5, 68.3, 69.0, 69.1, 69.2, 71.0, 71.8, 71.9, 72.1,
72.2, 72.8, 73.0, 73.4, 73.7, 74.1, 74.4, 74.7, 75.3, 75.4, 76.2, 76.3, 78.2, 78.9,
80.1, 96.9, 99.1, 118.4, 127.6, 127.7, 127.8, 127.9, 128.0, 122.1, 128.2, 128.3,
128.4, 128.5, 128.6, 128.7, 130.0, 130.1, 133.4, 133.5, 138.7, 139.0, 165.9,
170.3; IR (film): n˜ =3031, 2941, 2865, 1732, 1726, 1453, 1268, 1237, 1111,
1053 cmꢀ1; HRMS (ESI): m/z: calcd for C88H108NO18Si: 1494.7330; found
1494.7333 [M+NH4]+.
Allyl (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!2)-(3,4-di-
O-benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-(1!2)-(3,4,6-tri-O-
benzyl-a-d-mannopyranosyl)-(1!6)-2-O-benzoyl-3,4-di-O-benzyl-a-d-
mannopyranoside (28): Trisacharide acceptor 27 (450 mg, 0.31 mmol) and
mannose donor 12[17] (257 mg, 0.40 mmol) were azeotropically dried with
toluene (3ꢃ3 mL), dried in vacuo and dissolved in CH2Cl2 (5 mL). The
solution was cooled to 08C, followed by the addition of TMSOTf (4 mL,
20 mmol), and stirred for 1.5 h. The reaction was quenched by the addi-
tion of Et3N (0.5 mL) and the reaction mixture was concentrated. The
crude product was purified by chromatography (EtOAc/hexane 1:8 !
1:5) affording tetrasaccharide 28 (480 mg, 80%). Rf =0.29 (EtOAc/
hexane 1:4); [a]2D5 =+11.7 (c=1.00 in CH2Cl2); 1H NMR (CDCl3): d=
1.11 (s, 18H), 2.19 (s, 3H), 3.51–4.08 (m, 21H), 4.15–4.22 (m, 4H), 4.31
(d, J=12.1 Hz, 1H), 4.46–4.96 (m, 22H), 4.98 (s, 1H), 5.12 (s, 1H), 5.20
(d, J=10.3 Hz, 1H), 5.28–5.33 (dd, J=17.2, 1.4 Hz, 1H), 5.39 (s, 1H),
5.62–5.69 (m, 2H), 5.85–5.94 (m, 1H), 7.05–7.09 (m, 1H), 7.15–7.49 (m,
52H), 8.11 (d, J=7.0 Hz, 2H); 13C NMR (CDCl3): d=12.3, 18.3, 18.4,
21.4, 63.1, 66.8, 68.3, 68.9, 69.1, 69.4, 71.0, 71.9, 72.0, 72.1, 72.3, 72.4, 72.5,
73.5, 73.6, 73.7, 73.9, 74.5, 74.7, 75.0, 75.3, 75.4, 75.9, 78.9, 79.0, 79.8, 80.1,
96.9, 99.3, 100.2, 100.4, 118.4, 127.6, 127.7, 127.8, 127.9, 128.0, 128.1,
128.2, 128.3, 128.4, 128.5, 128.6, 128.7, 130.1, 130.2, 133.5, 133.6, 138.2,
138.3, 138.5, 138.6, 138.8, 138.9, 139.0, 139.1, 166.0, 170.4; IR (film): n˜ =
2939, 2865, 17745, 1726, 1497, 1454, 1365, 1269, 1237, 1112, 1055, 1028,
737 cmꢀ1; HRMS (ESI): m/z: calcd for C115H136NO23Si: 1926.9267; found
1926.9287 [M+NH4]+.
(2-O-Acetyl-3,4-di-O-benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-
(1!2)-(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-2-O-benzoyl-3,4-
di-O-benzyl-a-d-mannopyranosyl trichloroacetimidate (26): Compound
25 (475 mg, 0.32 mmol) was dissolved in AcOH (8 mL). Water (0.4 mL)
was added, followed by NaOAc (380 mg, 4.63 mmol) and PdCl2 (400 mg,
2.25 mmol), and the mixture was stirred for 24 h at room temperature.
The reaction mixture was diluted with EtOAc and washed with water, sa-
turated aqueous NaHCO3, and brine. The organic phase was dried over
MgSO4, filtered, concentrated and purified by chromatography (EtOAc/
hexane 1:6 ! 1:4) to give a lactol. This lactol was dissolved in CH2Cl2
(3 mL), and trichloroacetonitrile (1.5 mL) and DBU (12 mL) were added
at 08C. The mixture was stirred for 2 h and concentrated. Chromatogra-
phy (EtOAc/hexane 1:8) gave compound 26 (330 mg, 65% from 25). Rf =
0.47 (EtOAc/hexane 1:4); [a]2D5 =+25.0 (c=2.82 in CHCl3); 1H NMR
(CDCl3): d=0.95–1.18 (m, 21H), 2.13 (s, 3H), 3.61 (brd, J=9.9 Hz, 1H),
3.71 (dd, J=4.4, 11.1 Hz, 1H), 3.77–3.79 (m, 2H), 3.85–4.12 (m, 10H),
4.18–4.21 (m, 2H), 4.43–4.48 (m, 2H), 4.56–4.72 (m, 8H), 4.86–4.97 (m,
5H), 5.21 (d, J=1.6 Hz, 1H), 5.54 (s, 1H), 5.80 (t, J=2.6 Hz, 1H), 6.40
(d, J=1.8 Hz, 1H), 7.17–8.15 (m, 40H), 8.76 (s, 1H); 13C NMR (CDCl3):
d=12.5, 18.4, 18.5, 21.5, 63.0, 66.4, 68.2, 69.4, 72.2, 72.3, 72.4, 73.4, 73.6,
73.9, 74.0, 74.3, 74.9, 75.5, 75.6, 75.7, 78.3, 78.5, 80.5, 91.2, 95.5, 99.3, 99.4,
127.8, 127.9, 128.0, 128.1, 128.2, 128.3, 128.4, 128.5, 128.6, 128.7, 128.8,
128.9, 129.0, 130.0, 130.3, 133.9, 137.8, 138.4, 138.6, 138.9, 139.0, 139.3,
160.0, 165.9, 170.6; IR (film): n˜ =3031, 2941, 1730, 1453, 1368, 1263, 1238,
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!2)-(3,4-di-O-
benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-(1!2)-(3,4,6-tri-O-
benzyl-a-d-mannopyranosyl)-(1!6)-2-O-benzoyl-3,4-di-O-benzyl-a-d-
mannopyranosyl trichloroacetimidate (29): Tetrasaccharide 28 (600 mg,
0.31 mmol) was dissolved in AcOH (15 mL). Water (0.75 mL) was added,
followed by NaOAc (380 mg, 4.63 mmol) and PdCl2 (407 mg, 2.30 mmol),
and the mixture was stirred for 18 h at room temperature. The reaction
mixture was diluted with EtOAc and washed with water, saturated aque-
ous NaHCO3, and brine. The organic phase was dried over MgSO4, fil-
tered, concentrated and purified by chromatography (EtOAc/hexane 1:5
! 1:3) to give a lactol. The lactol was dissolved in CH2Cl2 (5 mL), and
trichloroacetonitrile (0.5 mL) and DBU (12 mL) were added at 08C. The
mixture was stirred for 2 h and concentrated. Chromatography (EtOAc/
hexane 1:6 ! 1:4) gave the imidate donor 29 (392 mg, 62% from 28).
1
Rf =0.57 (EtOAc/hexane 1:2); [a]2D5 =+21.4 (c=2.80 in CHCl3); H NMR
(CDCl3): d=1.07 (s, 18H), 2.15 (s, 3H), 3.48–3.77 (m, 7H), 3.82–4.18 (m,
18H), 4.27 (d, J=12.1 Hz, 1H), 4.40–4.64 (m, 13H), 4.67–4.92 (m, 9H),
5.33 (s, 1H), 5.58 (m, 1H), 5.76 (m, 1H), 7.05–7.47 (m, 53H), 8.09 (d, J=
6.8 Hz, 2H), 8.71 (s, 1H); 13C NMR (CDCl3): d=12.0, 18.4, 21.4, 62.4,
63.1, 66.5, 68.2, 69.0, 69.1, 69.4, 72.1, 72.2, 72.3, 72.4, 72.5, 73.5, 73.7, 73.8,
73.9, 74.0, 74.5, 75.0, 75.4, 75.5, 75.9, 77.0, 77.3, 77.5, 77.6, 78.3, 78.9, 79.9,
80.4, 82.4, 83.2, 88.1, 89.8, 91.1, 95.4, 96.4, 97.5, 99.2, 100.2, 100.4, 127.6,
127.7, 127.8, 127.9, 128.0, 128.1, 128.2, 128.3, 128.4, 128.5, 128.6, 128.7,
128.8, 129.9, 130.1, 133.7, 137.7, 138.3, 138.4, 138.5, 138.9, 139.0, 139.1,
139.2, 159.9, 165.7, 170.4; IR (film): n˜ =3339, 3031, 2940, 2864, 1730,
1676, 1497, 1454, 1365, 1264, 1237, 1093, 1028, 976, 698 cmꢀ1; HRMS
(ESI): m/z: calcd for C114H132Cl3N2O23Si: 2029.8050; found 2029.8121
[M+NH4]+.
1096, 1051 cmꢀ1
; HRMS (ESI): m/z: calcd for C87H100Cl3NO18SiNa:
1602.5667; found 1602.5601 [M+Na]+.
Allyl (3,4-di-O-benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-(1!2)-
(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-2-O-benzoyl-3,4-di-O-
benzyl-a-d-mannopyranoside (27): Trisaccharide 25 (1.01 g, 0.68 mmol)
was dissolved in THF (8 mL) and CH3OH (34 mL). To the reaction mix-
ture was added magnesium methoxide (7.7 wt%, 9 mL, 6.4 mmol) at
room temperature. After 4 h, acetic acid (1 mL) was added and the reac-
tion mixture was concentrated. The desired product, 27 (0.78 g, 78%)
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzo-
yl-3,4-di-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-
2500
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
Chem. Eur. J. 2005, 11, 2493 – 2504

Anchor Oligosaccharides
FULL PAPER
2-deoxy-a-d-glucopyranosyl)-(1!6)-1-O-allyl-2,3,4,5-tetra-O-benzyl-d-
myo-inositol (30): Disaccharide 11[13] (64 mg, 0.067 mmol) and dimannose
donor 23 (80 mg, 0.074 mmol) were azeotropically dried with toluene (3ꢃ
3 mL), dried in vacuo and dissolved in CH2Cl2 (3 mL). The solution was
cooled to 08C, followed by the addition of TMSOTf (3 mL, 16 mmol), and
stirred for 2 h. The reaction was quenched by the addition of Et3N
(0.05 mL) and the reaction mixture was concentrated. The crude product
was purified by chromatography (EtOAc/hexane 1:6 ! 1:3) affording
5.77 (d, J=3.6 Hz, 1H), 5.92–6.05 (m, 1H), 6.88–7.49 (m, 83H), 7.99–8.03
(m, 2H); 13C NMR (CDCl3): d=12.2, 18.4, 21.5, 62.8, 63.8, 66.4, 68.6,
69.0, 69.2, 69.8, 71.1, 71.4, 71.8, 72.1, 72.3, 72.4, 72.8, 73.0, 73.1, 73.5, 73.6,
73.7, 73.8, 74.4, 74.7, 74.8, 75.3, 75.5, 75.6, 75.8, 76.1, 77.5, 79.0, 79.1, 79.8,
80.1, 80.8, 81.2, 81.5, 82.1, 82.3, 97.9, 99.2, 99.3, 100.2, 117.4, 127.2, 127.3,
127.6, 127.8, 127.9, 128.0, 128.1, 128.2, 128.3, 128.4, 128.5, 128.6, 128.7,
130.0, 130.2, 133.4, 134.5, 137.7, 138.0, 138.1, 138.4, 138.5, 138.7, 138.8,
138.9, 139.0, 139.1, 139.2, 165.6, 170.4; IR (film): n˜ =3030, 2940, 2866,
2106, 1723, 1453, 1360, 1268, 1238, 1098, 1051 cmꢀ1; HRMS (MALDI-
TOF): m/z: calcd for C169H187N3O32SiNa: 2823.2822; found 2823.2798
[M+Na]+.
tetrasaccharide 30 (104 mg, 82%). Rf =0.16 (EtOAc/hexane 1:4); [a]D25
=
+60.6 (c=2.77 in CHCl3); 1H NMR (CDCl3): d=2.19 (s, 3H), 3.24 (dd,
J=2.2, 11.2 Hz, 1H), 3.30 (dd, J=3.7, 10.0 Hz, 1H), 3.35–3.63 (m, 9H),
3.77 (dd, J=2.5, 11.3 Hz, 1H), 3.90–4.10 (m, 10H), 4.20 (t, J=9.5 Hz,
1H), 4.32 (t, J=9.6 Hz, 1H), 4.36–4.48 (m, 7H), 4.62–5.01 (m, 15H), 5.10
(d, J=11.5 Hz, 1H), 5.24 (dd, J=1.4, 10.4 Hz, 1H), 5.34 (dd, J=1.4,
17.2 Hz, 1H), 5.53 (d, J=1.5 Hz, 1H), 5.58 (t, J=2.1 Hz, 1H), 5.74 (s,
1H), 5.79 (d, J=3.7 Hz, 1H), 5.94–6.04 (m, 1H), 7.07–7.52 (m, 58H),
8.07–8.10 (m, 2H); 13C NMR (CDCl3: d=21.6, 63.8, 66.3, 68.5, 68.8, 68.9,
69.4, 70.1, 71.2, 71.8, 71.9, 72.0, 73.2, 73.3, 73.8, 74.1, 74.4, 74.5, 74.6, 74.9,
75.3, 75.4, 75.6, 76.0, 76.3, 78.2, 79.0, 80.7, 81.3, 81.7, 82.2, 82.4, 98.1, 98.7,
99.5, 117.5, 127.4, 127.7, 127.9, 128.0, 128.1, 128.2, 128.3, 128.4, 128.5,
128.6, 128.7, 128.8, 128.9, 130.3, 130.4, 133.6, 134.6, 137.8, 138.0, 138.4,
138.6, 138.9, 139.0, 139.2, 139.3, 165.8, 170.6; IR (film): n˜ =3031, 2869,
2106, 1746, 1725, 1454, 1362, 1268, 1237, 1100, 1045 cmꢀ1; HRMS (ESI):
m/z: calcd for C113H117N3O22Na: 1890.8021; found 1890.8098 [M+Na]+.
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzo-
yl-3,4-di-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-
2-deoxy-a-d-glucopyranosyl)-(1!6)-2,3,4,5-tetra-O-benzyl-d-myo-inositol
(32): Compound 30 (115 mg, 0.06 mmol) was dissolved in AcOH (3 mL).
Water (0.15 mL) was added, followed by NaOAc (110 mg, 1.34 mmol)
and PdCl2 (105 mg, 0.59 mmol), and the mixture was stirred for 24 h at
room temperature. The reaction mixture was diluted with EtOAc and
washed with water, saturated aqueous NaHCO3, and brine. The organic
phase was dried over MgSO4, filtered, concentrated and purified by chro-
matography (EtOAc/hexane 1:5 ! 1:3) to give compound 32 (65 mg,
58%). Rf =0.32 (EtOAc/hexane 1:2); [a]2D5 =+52.6 (c=1.85 in CHCl3);
1H NMR (CDCl3): d=2.18 (s, 3H), 3.08 (d, J=6.7 Hz, 1H), 3.25–3.52 (m,
6H), 3.54 (dd, J=2.2, 9.9 Hz, 1H), 3.61–3.70 (m, 4H), 3.78 (dd, J=2.8,
10.9 Hz, 1H), 3.89–4.06 (m, 9H), 4.14 (dd, J=9.7, 10.5 Hz, 1H), 4.28–
4.46 (m, 7H), 4.61–5.09 (m, 16H), 5.51–5.55 (m, 3H),5.73 (t, J=2.2 Hz,
1H), 7.12–7.38 (m, 58H), 8.05–8.08 (m, 2H); 13C NMR (CDCl3): d=21.6,
64.6, 66.3, 68.5, 68.8, 68.9, 69.3, 70.9, 71.8, 72.0, 72.1, 72.2, 72.7, 73.4, 73.8,
74.1, 74.4, 74.7, 75.1, 75.3, 75.4, 75.5, 75.6, 76.3, 77.6, 78.2, 78.9, 80.6, 81.2,
81.3, 81.6, 82.3, 98.5, 98.7, 99.4, 127.9, 128.1, 128.2, 128.3, 128.4, 128.5,
128.6, 128.7, 128.8, 128.9, 130.3, 133.5, 137.5, 138.0, 138.4, 138.5, 138.6,
138.9, 139.1, 165.8, 170.6; IR (film): n˜ =3473, 3031, 2870, 2108, 1746,
1725, 1454, 1362, 1268, 1236, 1099, 1047 cmꢀ1; HRMS (ESI): m/z: calcd
for C110H117N4O22: 1845.8154; found 1845.8120 [M+NH4]+.
(2-O-Acetyl-3,4-di-O-benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-
(1!2)-(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-
di-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-
deoxy-a-d-glucopyranosyl)-(1!6)-1-O-allyl-2,3,4,5-tetra-O-benzyl-d-
myo-inositol (31): Disaccharide 11[13] (183 mg, 0.19 mmol) and triman-
nose donor 26 (330 mg, 0.21 mmol) were azeotropically dried with tolu-
ene (3ꢃ3 mL), dried in vacuo and dissolved in CH2Cl2 (6 mL). This so-
lution was cooled to ꢀ248C, followed by addition of TMSOTf (3.8 mL,
21 mmol), and stirred for 1 h. The reaction was quenched by addition of
Et3N (0.1 mL) and the reaction mixture was concentrated. The crude
product was purified by chromatography (EtOAc/toluene 1:30) affording
pentasaccharide 31 (430 mg, 94%). Rf =0.22 (EtOAc/toluene 1:25);
[a]2D5 =+39.4 (c=3.73 in CHCl3); 1H NMR (CDCl3): d=0.96–1.16 (m,
21H), 2.13 (s, 3H), 3.24 (dd, J=2.6, 11.3 Hz, 1H), 3.28–3.37 (m, 3H),
3.41–3.54 (m, 5H), 3.63–3.69 (m, 2H), 3.77 (brd, J=8.9 Hz, 1H), 3.90–
3.95 (m, 6H), 3.99–4.23 (m, 11H), 4.31–4.76 (m, 15H), 4.78–4.88 (m,
6H), 4.92–5.02 (m, 6H), 5.11 (d, J=11.3 Hz, 1H), 5.21 (d, J=1.5 Hz,
1H), 5.25 (dd, J=1.3, 10.4 Hz, 1H), 5.35 (dd, J=1.5, 17.2 Hz, 1H), 5.54
(t, J=2.4 Hz, 1H), 5.59 (d, J=1.5 Hz, 1H), 5.74 (s, 1H), 5.80 (d, J=
3.7 Hz, 1H), 5.97–6.04 (m, 1H), 7.07–7.48 (m, 68H), 8.04–8.06 (m, 2H);
13C NMR (CDCl3): d=12.5, 18.4, 18.5, 21.5, 62.9, 64.0, 66.6, 68.8, 69.2,
69.3, 69.4, 70.0, 71.2, 71.6, 71.8, 71.9, 72.0, 72.3, 72.4, 73.1, 73.3, 73.4, 73.6,
73.8, 74.0, 74.1, 74.5, 74.7, 74.8, 74.9, 75.1, 75.5, 75.7, 76.0, 76.3, 76.6, 77.0,
77.7, 78.4, 79.2, 80.4, 80.9, 81.3, 81.7, 82.2, 82.4, 98.1, 99.3, 99.4, 99.5,
117.5, 127.5, 127.9, 128.0, 128.1, 128.3, 128.4, 128.5, 128.6, 128.7, 128.8,
128.9, 130.2, 130.4, 133.6, 134.7, 137.8, 138.2, 138.4, 138.6, 138.7, 138.8,
138.9, 139.0, 139.2, 139.3, 139.4, 165.7, 170.6; IR (film): n˜ =3031, 2940,
2865, 2106, 1725, 1453, 1361, 1268, 1238, 1099, 1051 cmꢀ1; HRMS (ESI):
(2-O-Acetyl-3,4-di-O-benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-
(1!2)-(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-
di-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-
deoxy-a-d-glucopyranosyl)-(1!6)-2,3,4,5-tetra-O-benzyl-d-myo-inositol
(33): Compound 31 (400 mg, 0.17 mmol) was dissolved in AcOH
(10 mL). Water (0.5 mL) was added, followed by NaOAc (145 mg,
1.77 mmol) and PdCl2 (150 mg, 0.85 mmol), and the mixture was stirred
for 24 h at room temperature. The reaction mixture was diluted with
EtOAc and washed with water, saturated aqueous NaHCO3, and brine.
The organic phase was dried over MgSO4, filtered, concentrated and pu-
rified by chromatography (EtOAc/hexane 1:6 ! 1:4) to give compound
33 (216 mg, 55%). Rf =0.15 (EtOAc/hexane 1:4); [a]2D5 =+32.9 (c=1.73
in CHCl3); 1H NMR (CDCl3): d=1.08–1.14 (m, 21H), 2.11 (s, 3H), 3.07
(d, J=6.8 Hz, 1H), 3.25–3.36 (m, 3H), 3.40–3.51 (m, 4H), 3.54 (dd, J=
2.1, 9.9 Hz, 1H), 3.64–3.77 (m, 4H), 3.89–4.17 (m, 16H), 4.31–4.85 (m,
21H), 4.91–5.00 (m, 4H), 5.05–5.08 (m, 2H), 5.19 (d, J=1.7 Hz, 1H),
5.51–5.52 (m, 2H), 5.55 (d, J=1.5 Hz, 1H), 5.72 (brs, 1H), 7.11–7.38 (m,
68H), 8.04–8.07 (m, 2H); 13C NMR (CDCl3): d=12.5, 18.4, 18.5, 21.5,
62.9, 64.8, 68.8, 69.1, 69.2, 69.3, 70.8, 71.8, 71.9, 72.0, 72.3, 72.4, 73.4, 73.5,
73.6, 73.8, 74.0, 74.1, 74.6, 74.7, 75.1, 75.3, 75.5, 75.6, 75.7, 76.3, 77.6, 78.4,
79.1, 80.4, 80.5, 81.3, 81.4, 81.6, 82.3, 98.4, 99.2, 99.3, 99.4, 127.5, 127.9,
128.0, 128.2, 128.3, 128.4, 128.5, 128.6, 128.7, 128.8, 128.9, 130.2, 130.3,
133.6, 137.5, 138.2, 138.4, 138.5, 138.6, 138.9, 139.0, 139.2, 139.3, 165.7,
170.6; IR (film): n˜ =3031, 2940, 2865, 2107, 1725, 1453, 1362, 1268, 1238,
1097, 1050 cmꢀ1; HRMS (ESI): m/z: calcd for C139H163N5O27Si: 1181.0647;
m/z: calcd for C142H167N5O27Si: 1201.0803; found 1201.0796 [M+2NH4]2+
.
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!2)-(3,4-di-O-
benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-(1!2)-(3,4,6-tri-O-
benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-di-O-benzyl-a-d-
mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-deoxy-a-d-glucopyra-
nosyl)-(1!6)-1-O-allyl-2,3,4,5-tetra-O-benzyl-d-myo-inositol (9): Disac-
charide 11[13] (95 mg, 0.10 mmol) and tetramannose donor 29 (252 mg,
0.13 mmol) were coevaporated with toluene (3ꢃ3 mL), dried in vacuo
and dissolved in CH2Cl2 (5 mL). The solution was cooled to 08C, fol-
lowed by addition of TMSOTf (3.5 mL, 19 mmol), and stirred for 1.5 h.
The reaction was quenched by addition of Et3N (0.1 mL) and the reac-
tion mixture was concentrated. The crude product was purified by chro-
found 1181.0638 [M+2NH4]2+
.
(2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!2)-(3,4-di-O-
benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-(1!2)-(3,4,6-tri-O-
benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-di-O-benzyl-a-d-
mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-deoxy-a-d-glucopyra-
nosyl)-(1!6)-2,3,4,5-tetra-O-benzyl-d-myo-inositol (34): Hexasaccharide
9 (200 mg, 0.07 mmol) was dissolved in AcOH (8 mL). Water (0.4 mL)
was added, followed by NaOAc (96 mg, 1.17 mmol) and PdCl2 (100 mg,
0.56 mmol), and the mixture was stirred for 20 h at room temperature.
matography (EtOAc/hexane 1:7
!
1:5) affording hexasaccharide 9
(204 mg, 73%). Rf =0.55 (EtOAc/hexane 1:2); [a]2D5 =+36.6 (c=4.70 in
CHCl3); 1H NMR (CDCl3): d=1.03–1.11 (m, 21H), 2.16 (s, 3H), 3.19–
5.01 (m, 68H), 5.07–5.10 (m, 2H), 5.24 (dd, J=1.5, 10.5 Hz, 1H), 5.30–
5.37 (m, 2H), 5.56 (d, J=1.5 Hz, 1H), 5.62 (brs, 1H), 5.72 (brs, 1H),
Chem. Eur. J. 2005, 11, 2493 – 2504
www.chemeurj.org
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2501

P. H. Seeberger et al.
The reaction mixture was diluted with EtOAc and washed with water, sa-
turated aqueous NaHCO3, and brine. The organic phase was dried over
MgSO4, filtered, concentrated and purified by chromatography (EtOAc/
hexane 1:5) to give compound 34 (112 mg, 57%). Rf =0.42 (EtOAc/
hexane 1:2); [a]2D5 =+27.0 (c=2.05 in CHCl3); 1H NMR (CDCl3): d=
1.02–1.07 (m, 21H), 2.12 (s, 3H), 3.04 (d, J=6.9 Hz, 1H), 3.21–3.46
(m,9H), 3.50 (dd, J=2.2, 10.0 Hz, 1H), 3.56–5.06 (m, 58H), 5.32 (brs,
1H), 5.46 (d, J=3.6 Hz, 1H), 5.51 (d, J=1.8 Hz, 1H), 5.58 (t, J=2.1 Hz,
1H), 5.68 (t, J=2.4 Hz, 1H), 6.85–7.42 (m, 83H), 7.95–7.99 (m, 2H);
13C NMR (CDCl3): d=12.2, 18.4, 21.4, 62.8, 64.6, 66.4, 68.6, 69.0, 69.1,
69.2, 70.6, 71.5, 71.8, 71.9, 72.0, 72.2, 72.4, 72.7, 73.3, 73.4, 73.5, 73.6, 73.8,
74.3, 74.7, 74.8, 75.1, 75.3, 75.4, 75.6, 76.1, 77.5, 78.9, 79.8, 80.2, 80.3, 81.2,
81.4, 82.1, 98.1, 98.9, 99.3, 100.1, 127.3, 127.4, 127.6, 127.7, 127.8, 127.9,
128.0, 128.2, 128.3, 128.4, 128.5, 128.6, 128.7, 130.0, 133.4, 137.4, 138.0,
138.2, 138.3, 138.4, 138.7, 138.8, 138.9, 139.0, 139.1, 165.6, 170.4; IR
(film): n˜ =3031, 2940, 2864, 2106, 1725, 1452, 1363, 1268, 1239, 1097,
1051 cmꢀ1; HRMS (ESI): m/z: calcd for C166H183N3O32SiNa: 2783.2509;
found 2783.2444 [M+Na]+.
72.3, 72.5, 72.7, 73.5, 73.6, 73.8, 74.0, 74.1, 74.7, 75.1, 75.5, 75.7, 76.2, 77.1,
77.2, 77.6, 77.8, 78.4, 79.2, 80.3, 81.5, 82.1, 82.3, 99.3, 99.5, 99.8, 127.3,
127.5, 127.6, 127.8, 127.9, 128.0, 128.3, 128.5, 128.6, 128.7, 128.8, 128.9,
129.3, 130.2, 130.4, 133.6, 138.0, 138.3, 138.4, 138.7, 138.9, 139.0, 139.1,
139.3, 139.4, 140.3, 139.4, 165.7, 170.6; 31P NMR (CDCl3): d=0.34; IR
(film): n˜ =3030, 2940, 2865, 2107, 1726, 1453, 1361, 1268, 1237, 1097,
1051 cmꢀ1; HRMS (ESI): m/z: calcd for C152H173N3O30PSSi: 2611.1332;
found 2611.1295 [M]ꢀ.
Triethylammonium (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-
(1!2)-(3,4-di-O-benzyl-6-O-triisopropylsilyl-a-d-mannopyranosyl)-(1!
2)-(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-di-
O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-deoxy-
a-d-glucopyranosyl)-(1!6)-2,3,4,5-tetra-O-benzyl-1-O-(6-(S-benzyl)thio-
hexyl phosphono)-d-myo-inositol (37):
A mixture of compound 34
(110 mg, 0.04 mmol) and H-phosphonate 17 (115 mg, 0.40 mmol) was co-
evaporated with pyridine (3ꢃ3 mL) and dried in vacuo. To the residue in
pyridine (2.5 mL) was added pivaloyl chloride (100 mL, 0.81 mmol) at
room temperature. After 4 h, water (0.2 mL) and iodine (110 mg,
0.43 mmol) were added. After 40 min, the mixture was diluted with
CH2Cl2 and washed with 1m Na2S2O3 and water. The organic layer was
dried over MgSO4, filtered and concentrated. Chromatography (CH3OH/
CH2Cl2 gradient with 1% Et3N) afforded phosphodiester 37 (120 mg,
96%). Rf =0.35 (CH3OH/CH2Cl2 1:10); [a]2D5 =+38.7 (c=1.35 in CHCl3);
1H NMR (CDCl3): d=1.02–1.06 (m, 21H), 1.21–1.61 (m, 19H), 2.11 (s,
3H), 2.36 (t, J=7.4 Hz, 2H), 2.97 (q, J=7.2 Hz, 6H), 3.13 (dd, J=3.7,
10.0 Hz, 1H), 3.25 (d, J=9.9 Hz, 1H), 3.31–5.06 (m, 68H), 5.32 (brs,
1H), 5.46 (brs, 1H), 5.57 (brs, 1H), 5.62 (brs, 1H), 5.91 (d, J=3.9 Hz,
1H), 6.81–7.45 (m, 88H), 7.94–7.98 (m, 2H); 13C NMR (CDCl3): d=8.6,
12.1, 18.3, 21.3, 25.5, 28.8, 29.3, 31.4, 36.3, 45.48, 62.6, 63.5, 65.8, 66.1,
68.4, 68.6, 68.7, 69.1, 69.5, 71.1, 71.6, 71.8, 72.0, 72.2, 72.3, 72.4, 73.2, 73.4,
73.5, 74.1, 74.4, 74.5, 74.7, 75.1, 75.3, 75.7, 77.3, 78.7, 78.9, 79.6, 79.8, 80.3,
81.1, 81.6, 81.9, 96.7, 99.1, 99.3, 99.9, 126.8, 126.9, 127.0, 127.1, 127.3,
127.4, 127.5, 127.6, 127.7, 127.8, 127.9, 128.0, 128.1, 128.2, 128.3, 128.4,
128.7, 129.6, 129.9, 133.0, 137.4, 137.5, 137.8, 138.0, 138.1, 138.4, 138.5,
138.7, 138.8, 139.8, 165.1, 169.9; 31P NMR (CDCl3): d=ꢀ0.75; IR (film):
Triethylammonium (2-O-Acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-
(1!6)-(2-O-benzoyl-3,4-di-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-
azido-3,6-di-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-2,3,4,5-tetra-
O-benzyl-1-O-(6-(S-benzyl)thiohexyl phosphono)-d-myo-inositol (35): A
mixture of compound 32 (142 mg, 0.08 mmol) and H-phosphonate 17
(200 mg, 0.69 mmol) was coevaporated with pyridine (3ꢃ3 mL) and dried
in vacuo. To the residue in pyridine (2 mL) was added pivaloyl chloride
(170 mL, 1.38 mmol) at room temperature. After 3 h, water (0.15 mL) and
iodine (190 mg, 0.75 mmol) were added. After 1 h, the mixture was dilut-
ed with CH2Cl2 and washed with 1m Na2S2O3 and water. The organic
phase was dried over MgSO4, filtered and concentrated. Chromatography
(CH3OH/CH2Cl2 gradient with 1% Et3N) afforded phosphodiester 35
(141 mg, 83%). Rf =0.35 (CH3OH/CH2Cl2 1:10); [a]2D5 =+63.1 (c=1.30 in
CHCl3); 1H NMR (CDCl3): d=1.23–1.66 (m, 19H), 2.18 (s, 3H), 2.41 (t,
J=7.4 Hz, 2H), 2.94 (q, J=7.2 Hz, 6H), 3.21 (dd, J=3.7, 10.0 Hz, 1H),
3.40–3.78 (m, 10H), 3.86–4.03 (m, 7H), 4.09 (t, J=9.4 Hz, 1H), 4.15–4.24
(m, 2H), 4.33–4.52 (m, 9H), 4.64–4.77 (m, 5H), 4.81–4.97 (m, 9H), 5.02–
5.12 (m, 3H), 5.51 (s, 1H), 5.58 (s, 1H), 5.69 (s, 1H), 6.01 (d, J=3.6 Hz,
1H), 7.20–7.51 (m, 63H), 8.07–8.09 (m, 2H); 13C NMR (CDCl3): d=9.3,
21.6, 25.9, 29.2, 29.6, 31.3, 31.4, 31.7, 36.7, 45.8, 63.5, 66.0, 66.1, 66.3, 68.5,
68.9, 69.1, 69.4, 69.9, 71.8, 71.9, 72.0, 72.7, 73.6, 73.8, 74.1, 74.4, 74.5, 74.8,
74.9, 75.1, 75.4, 75.5, 76.1, 76.2, 77.1, 77.7, 77.8, 78.2, 79.0, 80.5, 81.5, 82.1,
82.3, 97.1, 98.8, 99.8, 127.5, 127.6, 127.7, 127.8, 127.9, 128.0, 128.1, 128.2,
128.3, 128.5, 128.6, 128.7, 128.8, 128.9, 129.3, 130.3, 130.4, 133.6, 137.9,
138.0, 138.4, 138.6, 138.7, 139.0, 139.1, 139.3, 140.4, 165.8, 170.6; 31P NMR
(CDCl3): d=0.33; IR (film): n˜ =3030, 2933, 2107, 1745, 1725, 1453, 1362,
n˜ =3030, 2939, 2865, 2106, 1725, 1453, 1360, 1268, 1237, 1098, 1050 cmꢀ1
(a-d-Mannopyranosyl)-(1!6)-(a-d-mannopyranosyl)-(1!4)-(2-amino-2-
.
deoxy-a-d-glucopyranosyl)-(1!6)-1-O-(6-thiohexyl phosphono)-d-myo-
inositol (5): Sodium methoxide (25 wt%, 0.06 mL, 0.26 mmol) was added
to a solution of phosphodiester 35 (42 mg, 0.02 mmol) in CH3OH/CH2Cl2
(1.5:0.5, 2 mL). After stirring for 4 h at 608C, the mixture was neutralized
with Amberlite IR-120, filtered, and evaporated under reduced pressure.
The crude product was purified by chromatography (CH3OH/CH2Cl2 gra-
dient with 1% Et3N) to give the diol. Ammonia (~20 mL) was condensed
in a flame-dried three-necked flask at ꢀ788C. Sodium metal was added
portionwise until the solution was dark blue. The obtained diol in THF
(7 mL) was added via cannula, followed by CH3OH (0.2 mL). The resul-
tant dark blue solution was stirred at ꢀ788C for 30 min. Following disap-
pearance of the blue color, EtOH (2 mL) and AcOH (~0.5 mL) were
added and ammonia was blown off with a stream of Ar. Chromatography
of the crude mixture on Sephadex G-25 (EtOH/H2O 1:1), followed by di-
alysis and lyophilization afforded a mixture of the target compound 5
and the corresponding disulfide (9.5 mg, 58%). 1H NMR (D2O): d=
1.31–1.70 (m, 10H), 2.75 (t, J=7.2 Hz, 2H), 3.32 (dd, J=3.6, 10.8 Hz,
1H), 3.39 (t, J=9.3 Hz, 1H), 3.49–4.22 (m, 22H), 4.87 (d, J=1.3 Hz,
1H), 5.21 (d, J=1.5 Hz, 1H), 5.49 (d, J=3.7 Hz, 1H); 13C NMR (D2O):
d=24.9, 27.5, 28.5, 30.0, 38.4, 55.0, 60.6, 61.2, 62.7, 66.3, 66.6, 66.7, 66.8,
67.0, 68.7, 70.2, 70.5, 70.7, 70.8, 71.4, 71.6, 72.4, 72.5, 72.9, 73.5, 76.1, 77.1,
100.0, 102.1; 31P NMR (D2O): d=1.44; HRMS (ESI): m/z: calcd for
C60H111N2O46P2S2: 1721.5319; found 1721.5348 [M+H]+.
1268, 1235, 1098, 1051 cmꢀ1
;
HRMS (ESI): m/z: calcd for
C123H131N3O25PS: 2112.8535; found 2112.8500 [M]ꢀ.
Triethylammonium (2-O-acetyl-3,4-di-O-benzyl-6-O-triisopropylsilyl-a-d-
mannopyranosyl)-(1!2)-(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!
6)-(2-O-benzoyl-3,4-di-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-
3,6-di-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-2,3,4,5-tetra-O-
benzyl-1-O-(6-(S-benzyl)thiohexyl phosphono)-d-myo-inositol (36):
A
mixture of compound 33 (200 mg, 0.09 mmol) and H-phosphonate 17
(167 mg, 0.58 mmol) was coevaporated with pyridine (3ꢃ3 mL) and dried
in vacuo. To the solution of the residue in pyridine (2.5 mL) was added
pivaloyl chloride (140 mL, 1.13 mmol) at room temperature. After 3 h,
water (0.2 mL) and iodine (160 mg, 0.63 mmol) were added. After
50 min, the mixture was diluted with CH2Cl2 and washed with 1m
Na2S2O3 and water. The organic phase was dried over MgSO4, filtered
and concentrated. Chromatography (CH3OH/CH2Cl2 gradient with 1%
Et3N) afforded phosphodiester 36 (222 mg, 95%). Rf =0.39 (CH3OH/
CH2Cl2 1:10); [a]2D5 =+41.1 (c=2.09 in CHCl3); 1H NMR (CDCl3): d=
1.06–1.10 (m, 21H), 1.22–1.63 (m, 19H), 2.09 (s, 3H), 2.38 (t, J=7.4 Hz,
2H), 2.92 (q, J=7.2 Hz, 6H), 3.16 (dd, J=3.7, 9.9 Hz, 1H), 3.29 (d, J=
9.7 Hz, 1H), 3.40–3.60 (m, 8H), 3.69–3.75 (m, 3H), 3.87–3.96 (m, 7H),
4.02–4.17 (m, 6H), 4.22–4.37 (m, 4H), 4.40–4.72 (m, 14H), 4.77–4.93 (m,
10H), 4.99–5.08 (m, 3H), 5.16 (brs, 1H), 5.43 (brs, 2H), 5.64 (brs, 1H),
5.98 (d, J=3.7 Hz, 1H), 7.05–7.45 (m, 73H), 7.99–8.01 (m, 2H);
13C NMR (CDCl3): d=8.9, 12.5, 18.5, 18.6, 21.5, 25.9, 29.2, 29.6, 31.7,
36.7, 45.8, 62.9, 63.7, 66.2, 66.3, 66.6, 66.7, 69.2, 69.3, 69.5, 69.9, 71.6, 72.0,
Triethylammonium
(2-O-acetyl-3,4-di-O-benzyl-a-d-mannopyranosyl)-
(1!2)-(3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-
di-O-benzyl-a-d-mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-
deoxy-a-d-glucopyranosyl)-(1!6)-2,3,4,5-tetra-O-benzyl-1-O-(6-(S-ben-
zyl)thiohexyl phosphono)-d-myo-inositol (38): Scandium trifluorometha-
nesulfonate (50 mg, 0.1 mmol) and water (20 mL) were added to a so-
lution of compound 36 (135 mg, 0.05 mmol) in CH3CN. After being stir-
red for 4.5 h at 508C, the mixture was diluted with CH2Cl2 and washed
2502
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
Chem. Eur. J. 2005, 11, 2493 – 2504

Anchor Oligosaccharides
FULL PAPER
with brine. The organic phase was dried over MgSO4, filtered and con-
centrated. Chromatography (CH3OH/CH2Cl2 gradient with 1% Et3N) af-
forded compound 38 (97 mg, 76%). Rf =0.39 (CH3OH/CH2Cl2 1:10);
[a]2D5 =+46.9 (c=2.85 in CHCl3); 1H NMR (CDCl3): d=1.22–1.66 (m,
19H), 1.84 (dd, J=5.0, 7.4 Hz, 1H), 2.16 (s, 3H), 2.41 (t, J=7.4 Hz, 2H),
2.92 (q, J=7.3 Hz, 6H), 3.21 (dd, J=3.7, 10.0 Hz, 1H), 3.40–3.74 (m,
12H), 3.78–4.01 (m, 10H), 4.06–4.11 (m, 2H), 4.17 (t, J=9.5 Hz, 1H),
4.22–4.26 (m, 1H), 4.36–4.48 (m, 8H), 4.57–5.11 (m, 23H), 5.53 (brs,
1H), 5.55 (dd, J=1.8, 3.0 Hz, 1H), 5.65 (brs, 1H), 6.01 (d, J=3.7 Hz,
1H), 7.06–7.47 (m, 73H), 8.03–8.05 (m, 2H); 13C NMR (CDCl3): d=9.3,
21.6, 25.9, 29.2, 29.6, 31.3, 31.4, 31.7, 36.7, 45.9, 62.1, 63.7, 66.0, 66.1, 66.4,
69.1, 69.2, 69.7, 69.9, 72.0, 72.1, 72.2, 72.3, 72.4, 72.7, 72.8, 73.6, 74.1, 74.5,
74.7, 74.8, 75.1, 75.3, 75.4, 75.5, 75.6, 76.2, 77.1, 77.7, 77.8, 78.4, 79.0, 79.8,
80.7, 81.5, 82.1, 82.3, 97.0, 99.5, 99.6, 99.9, 127.5, 127.7, 127.8, 127.9, 128.1,
128.3, 128.4, 128.5, 128.6, 128.7, 128.8, 128.9, 129.3, 130.2, 130.4, 133.6,
138.0, 138.4, 138.5, 138.8, 138.9, 139.0, 139.1, 139.2, 140.4, 165.7, 170.4;
31P NMR (CDCl3): d=0.30; IR (film): n˜ =3030, 2931, 2107, 1734, 1453,
(a-d-Mannopyranosyl)-(1!2)-(a-d-mannopyranosyl)-(1!2)-(a-d-man-
nopyranosyl)-(1!6)-(a-d-mannopyranosyl)-(1!4)-(2-amino-2-deoxy-a-
d-glucopyranosyl)-(1!6)-1-O-(6-thiohexyl
phosphono)-d-myo-inositol
(8): Sodium methoxide (25wt%, 0.1 mL, 0.43 mmol) was added to a so-
lution of phosphodiester 39 (37 mg, 0.01 mmol) in CH3OH/CH2Cl2
(1.5:0.5, 2 mL). After stirring for 5 h at 608C, the mixture was neutralized
with Amberlite IR-120, filtered, and evaporated under reduced pressure.
The crude product was purified by chromatography (CH3OH/CH2Cl2 gra-
dient with 1% Et3N) to give the diol. Ammonia (~20 mL) was condensed
in a flame-dried three-necked flask at ꢀ788C. Sodium metal was added
portionwise until the solution was dark blue. The obtained diol in THF
(8 mL) was added via cannula, followed by CH3OH (0.15 mL). The resul-
tant dark blue solution was stirred at ꢀ788C for 30 min. Following disap-
pearance of the blue color, EtOH (2 mL) and AcOH (~0.5 mL) were
added and ammonia was blown off with a stream of Ar. Chromatography
of the crude mixture on Sephadex G-25 (EtOH/H2O 1:1), followed by di-
alysis and lyophilization afforded a mixture of the target compound 8
and the corresponding disulfide (9 mg, 61%). 1H NMR (D2O): d=1.27–
1.76 (m, 10H), 2.79 (t, J=6.9 Hz, 2H), 3.27–4.22 (m, 36H), 5.05 (d, J=
1.8 Hz, 1H), 5.13 (brs, 1H), 5.24 (brs, 1H), 5.29 (brs, 1H); 13C NMR
(D2O): d=24.9, 27.5, 28.6, 30.0, 38.4, 61.2, 61.3, 61.4, 62.8, 66.7, 66.8, 67.1,
67.2, 67.3, 70.2, 70.3, 70.5, 70.6, 70.8, 70.9, 71.6, 72.3, 72.5, 72.6, 73.0, 73.5,
76.2, 78.7, 79.0, 98.7, 100.9, 102.5; 31P NMR (D2O): d=0.77; HRMS
(ESI): m/z: calcd for C84H152N2O66P2S2: 1185.3752; found 1185.3751
1363, 1268, 1235, 1096, 1050 cmꢀ1
143H153N3O30PS: 2455.0003; found 2454.9915 [M]ꢀ.
; HRMS (ESI): m/z: calcd for
C
Triethylammonium (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyranosyl)-
(1!2)-(3,4-di-O-benzyl-a-d-mannopyranosyl)-(1!2)-(3,4,6-tri-O-benzyl-
a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-di-O-benzyl-a-d-manno-
pyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-deoxy-a-d-glucopyranosyl)-
(1!6)-2,3,4,5-tetra-O-benzyl-1-O-(6-(S-benzyl)thiohexyl phosphono)-d-
myo-inositol (39): Scandium trifluoromethanesulfonate (37 mg,
0.075 mmol) and water (20 mL) were added to a solution of compound 37
(115 mg, 0.037 mmol) in CH3CN. After being stirred for 5 h at 508C, the
mixture was diluted with CH2Cl2 and washed with brine. The organic
phase was dried over MgSO4, filtered and concentrated. Chromatography
(CH3OH/CH2Cl2 gradient with 1% Et3N) afforded compound 39 (86 mg,
79%). Rf =0.35 (CH3OH/CH2Cl2 1:10); [a]2D5 =+44.8 (c=1.02 in CHCl3);
1H NMR (CDCl3): d=1.19–1.61 (m, 19H), 2.12 (s, 3H), 2.36 (t, J=
7.5 Hz, 2H), 2.95 (q, J=7.2 Hz, 6H), 3.14 (dd, J=3.9, 9.9 Hz, 1H), 3.26–
5.02 (m, 68H), 5.06 (d, J=1.5 Hz, 1H), 5.15 (d, J=1.5 Hz, 1H), 5.44 (d,
J=1.5 Hz, 1H), 5.54 (t, J=2.4 Hz, 1H), 5.59 (brs, 1H), 5.94 (d, J=
3.9 Hz, 1H), 6.91–7.45 (m, 88H), 7.94–7.97 (m, 2H); 13C NMR (CDCl3):
d=8.7, 21.4, 25.6, 28.9, 29.4, 31.5, 36.5, 45.6, 62.0, 63.5, 68.7, 68.9, 69.0,
69.4, 69.7, 71.6, 71.8, 72.0, 72.3, 72.5, 72.9, 73.5, 73.6, 73.8, 74.3, 74.4, 74.7,
74.9, 75.2, 75.5, 75.9, 77.5, 78.2, 78.9, 79.4, 79.6, 81.2, 81.8, 82.1, 96.9, 99.3,
99.5, 100.4, 127.1, 127.2, 127.4, 127.7, 127.8, 128.0, 128.3, 128.4, 128.5,
129.0, 129.9, 130.2, 133.4, 137.8, 138.1, 138.2, 138.5, 138.6, 138.7, 138.8,
138.9, 139.1, 140.1, 165.5, 170.3; 31P NMR (CDCl3): d=ꢀ0.10; IR (film):
[M+2H]2+
.
Bistriethylammonium (2-O-acetyl-3,4-di-O-benzyl-6-O-(2-(N-benzyloxy-
carbonyl)aminoethyl phosphono)-a-d-mannopyranosyl)-(1!2)-(3,4,6-tri-
O-benzyl-a-d-mannopyranosyl)-(1!6)-(2-O-benzoyl-3,4-di-O-benzyl-a-
d-mannopyranosyl)-(1!4)-(2-azido-3,6-di-O-benzyl-2-deoxy-a-d-gluco-
pyranosyl)-(1!6)-2,3,4,5-tetra-O-benzyl-1-O-(6-(S-benzyl)thiohexyl
phosphono)-d-myo-inositol (41): A mixture of compound 38 (74 mg,
0.03 mmol) and H-phosphonate 40[17] (150 mg, 0.42 mmol) was coevapo-
rated with pyridine (3ꢃ3 mL) and dried in vacuo. To the residue in pyri-
dine (2 mL) was added pivaloyl chloride (110 mL, 0.89 mmol) at room
temperature. After 4 h, water (0.2 mL) and iodine (110 mg, 0.43 mmol)
were added. After 1 h, the mixture was diluted with CH2Cl2 and washed
with 1m Na2S2O3 and water. The organic phase was dried over MgSO4,
filtered and concentrated. Chromatography (CH3OH/CH2Cl2 gradient
with 1% Et3N) afforded compound 41 (52 mg, 62%). Rf =0.2 (CH3OH/
CH2Cl2 1:10); [a]2D5 =+34.2 (c=1.30 in CHCl3); 1H NMR (CDCl3): d=
1.23–1.58 (m, 28H), 2.04 (s, 3H), 2.35 (t, J=7.4 Hz, 2H), 2.91 (q, J=
7.3 Hz, 12H), 3.10 (dd, J=3.7, 10.0 Hz, 1H), 3.19–3.64 (m, 14H), 3.81–
4.12 (m, 15H), 4.20–4.49 (m, 13H), 4.56–4.88 (m, 15H), 4.93–5.05 (m,
6H), 5.47 (brs, 1H), 5.49 (brs, 1H), 5.55 (s, 1H), 5.60 (brs, 1H), 5.93 (d,
J=3.6 Hz, 1H), 6.72 (brs, 1H), 7.06–7.32 (m, 78H), 7.96–7.98 (m, 2H);
13C NMR (CDCl3): d=8.5, 9.6, 21.5, 25.8, 29.1, 29.5, 30.1, 31.4, 31.7, 36.6,
46.2, 53.3, 63.7, 64.5, 65.9, 66.6, 69.1, 69.5, 69.8, 71.5, 72.0, 72.1, 72.3, 72.7,
73.5, 73.9, 74.2, 74.7, 74.8, 75.0, 75.2, 75.3, 75.4, 76.1, 77.1, 77.7, 77.8, 79.2,
80.0, 80.7, 81.5, 82.1, 82.3, 96.9, 99.2, 99.5, 99.8, 127.2, 127.3, 127.4, 127.7,
127.8, 128.0, 128.1, 128.2, 128.3, 128.4, 128.5, 128.6, 128.7, 128.8, 129.2,
130.1, 130.3, 133.6, 137.3, 137.9, 138.2, 138.3, 138.5, 138.6, 138.8, 138.9,
139.0, 139.2, 139.3, 140.3, 156.9, 165.7, 170.4; 31P NMR (CDCl3): d=0.15,
n˜ =3030, 2930, 2107, 1732, 1453, 1361, 1268, 1235, 1095, 1051 cmꢀ1
.
(a-d-Mannopyranosyl)-(1!2)-(a-d-mannopyranosyl)-(1!6)-(a-d-man-
nopyranosyl)-(1!4)-(2-amino-2-deoxy-a-d-glucopyranosyl)-(1!6)-1-O-
(6-thiohexyl phosphono)-d-myo-inositol (6): Sodium methoxide (25wt%,
0.1 mL, 0.43 mmol) was added to a solution of phosphodiester 38 (57 mg,
0.02 mmol) in CH3OH/CH2Cl2 (1.5:0.5, 2 mL). After stirring for 5 h at
608C, the mixture was neutralized with Amberlite IR-120, filtered, and
evaporated under reduced pressure. The crude product was purified by
chromatography (CH3OH/CH2Cl2 gradient with 1% Et3N) to give the
diol. Ammonia (~20 mL) was condensed in a flame-dried three-necked
flask at ꢀ788C. Sodium metal was added portionwise until the solution
was dark blue. The obtained diol in THF (8 mL) was added via cannula,
followed by CH3OH (0.15 mL). The resultant dark blue solution was stir-
red at ꢀ788C for 30 min. Following disappearance of the blue color,
EtOH (2 mL) and AcOH (~0.5 mL) were added and ammonia was
blown off with a stream of Ar. Chromatography of the crude mixture on
Sephadex G-25 (EtOH/H2O 1:1), followed by dialysis and lyophilization
afforded a mixture of the target compound 6 and the corresponding di-
sulfide (13.5 mg, 59%). 1H NMR (D2O): d=1.30–1.79 (m, 10H), 2.83 (t,
J=7.2 Hz, 2H), 3.34–4.29 (m, 30H), 5.09 (brs, 1H), 5.19 (brs, 1H), 5.28
(brs, 1H), 5.36 (m, 1H); 13C NMR (D2O): d=25.0, 27.5, 28.6, 30.0, 38.4,
55.4, 60.8, 61.2, 61.4, 62.8, 66.5, 66.7, 66.8, 67.1, 67.2, 70.2, 70.4, 70.5, 70.6,
70.7, 70.8, 71.5, 72.4, 72.5, 73.0, 73.5, 76.0, 77.5, 78.9, 98.7, 102.2, 102.5;
31P NMR (D2O): d=1.25; HRMS (ESI): m/z: calcd for C36H66NO28PSNa:
1046.3122; found 1046.3135 [M+Na]+.
2.39; IR (film): n˜ =3030, 2935, 2107, 1718, 1454, 1363, 1234, 1048 cmꢀ1
HRMS (ESI): m/z: calcd for 153H164N4O35P2S: 1355.5181; found
1355.5192 [M]2ꢀ
;
C
.
Bistriethylammonium (2-O-acetyl-3,4,6-tri-O-benzyl-a-d-mannopyrano-
syl)-(1!2)-(3,4-di-O-benzyl-6-O-(2-(N-benzyloxycarbonyl)aminoethyl
phosphono)-a-d-mannopyranosyl)-(1!2)-(3,4,6-tri-O-benzyl-a-d-manno-
pyranosyl)-(1!6)-(2-O-benzoyl-3,4-di-O-benzyl-a-d-mannopyranosyl)-
(1!4)-(2-azido-3,6-di-O-benzyl-2-deoxy-a-d-glucopyranosyl)-(1!6)-
2,3,4,5-tetra-O-benzyl-1-O-(6-(S-benzyl)thiohexyl phosphono)-d-myo-in-
ositol (42): A mixture of compound 39 (47 mg, 0.016 mmol) and H-phos-
phonate 40[12] (41 mg, 0.16 mmol) was coevaporated with pyridine (3ꢃ
3 mL) and dried in vacuo. To the residue in pyridine (2 mL) was added
pivaloyl chloride (40 mL, 0.89 mmol) at room temperature. After 5 h,
water (0.1 mL) and iodine (43 mg, 0.17 mmol) were added. After 30 min,
the mixture was diluted with CH2Cl2 and washed with 1m Na2S2O3 and
water. The organic phase was dried over MgSO4, filtered and concentrat-
ed. Chromatography (CH3OH/CH2Cl2 gradient with 1% Et3N) afforded
Chem. Eur. J. 2005, 11, 2493 – 2504
www.chemeurj.org
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2503

P. H. Seeberger et al.
compound 42 (38 mg, 72%). Rf =0.25 (CH3OH/CH2Cl2 1:10); [a]D25
=
Acknowledgement
+19.3 (c=1.15 in CHCl3); 1H NMR (CDCl3): d=1.20–1.56 (m, 28H),
2.06 (s, 3H), 2.33 (t, J=7.4 Hz, 2H), 3.03 (q, J=7.3 Hz, 12H), 3.23–4.98
(m, 75H), 5.06 (brs, 1H), 5.16 (brs, 1H), 5.41 (brs, 1H), 5.53 (brs, 1H),
5.57 (brs, 1H), 5.88 (d, J=3.7 Hz, 1H), 6.64 (brs, 1H), 6.94–7.39 (m,
93H), 7.91–7.94 (m, 2H); 13C NMR (CDCl3): d=8.3, 8.8, 20.3, 25.5, 27.7,
29.3, 29.85, 31.4, 36.3, 38.7, 45.7, 53.0, 63.4, 64.1, 64.6, 65.6, 65.7, 66.1,
66.2, 68.4, 68.6, 68.7, 69.0, 69.1, 69.4, 71.1, 71.5, 71.6, 71.7, 72.0, 72.1, 72.3,
73.0, 73.2, 73.3, 73.5, 74.0, 74.2, 74.3, 74.4, 74.6, 74.8, 75.0, 75.2, 75.7, 76.1,
76.3, 77.3, 78.4, 78.8, 79.4, 79.5, 80.3, 81.0, 81.6, 81.8, 96.4, 98.8, 99.0, 99.1,
100.2, 126.7, 126.8, 126.9, 127.2, 127.3, 127.5, 127.6, 127.8, 127.9, 128.0,
128.1, 128.2, 128.3, 128.7, 129.6, 129.8, 133.1, 134.7, 136.8, 137.4, 137.7,
137.9, 138.0, 138.3, 138.4, 138.7, 139.7, 156.3, 165.2, 169.9; 31P NMR
(CDCl3): d=ꢀ0.88, 1.56; IR (film): n˜ =3031, 2935, 2106, 1718, 1454,
This work was supported by GlaxoSmithKline (Scholar Award to P.H.S.),
the Alfred P. Sloan Foundation (Fellowship to P.H.S.) and Merck (Aca-
demic Development Award to P.H.S). Y.-U. Kwon thanks Korea Science
and Engineering Foundation (KOSEF) for financial support (Postdoc-
toral Fellowship).
[1] WHO, Weekly Epidemiological Record 1996, 71, 17–24.
[2] M. F. Good, Nat. Rev. Immunol. 2001, 1, 117–125.
[3] C. A. W. Bate, J. Taverne, H. J. Bootsma, R. C. S. Mason, N. Skalko,
G. Gregoriadidis, J. H. L. Playfair, Immunology 1992, 76, 35–41.
[4] L. Schofield, F. Hackett, J. Exp. Med. 1993, 177, 145–153.
[5] S. D. Tachado, L. Schofield, Biochem. Biophys. Res. Commun. 1994,
205, 984–991.
1362, 1234, 1050 cmꢀ1
.
(6-O-(2-Aminoethyl phosphono)a-d-mannopyranosyl)-(1!2)-(a-d-man-
nopyranosyl)-(1!6)-(a-d-mannopyranosyl)-(1!4)-(2-amino-2-deoxy-a-
[6] P. Gerold, A. Dieckmann-Schuppert, R. T. Schwarz, J. Biol. Chem.
1994, 269, 2597–2606.
d-glucopyranosyl)-(1!6)-1-O-(6-thiohexyl
phosphono)-d-myo-inositol
(7): Sodium methoxide (25wt%, 0.1 mL, 0.43 mmol) was added to a so-
lution of phosphodiester 41 (50 mg, 0.02 mmol) in CH3OH/CH2Cl2
(1.5:0.5, 2 mL). After stirring for 5 h at 608C, the mixture was neutralized
with Amberlite IR-120, filtered, and evaporated under reduced pressure.
The crude product was purified by chromatography (CH3OH/CH2Cl2 gra-
dient with 1% Et3N) to give the diol. Ammonia (~20 mL) was condensed
in a flame-dried three-necked flask at ꢀ788C. Sodium metal was added
portionwise until the solution was dark blue. The obtained diol in THF
(8 mL) was added via cannula, followed by CH3OH (0.2 mL). The resul-
tant dark blue solution was stirred at ꢀ788C for 30 min. Following disap-
pearance of the blue color, EtOH (2 mL) and AcOH (~0.5 mL) were
added and ammonia was blown off with a stream of Ar. Chromatography
of the crude mixture on Sephadex G-25 (EtOH/H2O 1:1), followed by di-
alysis and lyophilization afforded a mixture of the target compound 7
[7] L. Schofield, S. Novakovic, P. Gerold, R. T. Schwarz, M. J. McCon-
ville, S. D. Tachado, J. Immunol. 1996, 156, 1886–1896.
[8] S. D. Tachado, P. Gerold, M. J. McConville, T. Baldwin, D. Quilici,
R. T. Schwarz, L. Schofield, Proc. Natl. Acad. Sci. USA 1997, 94,
4022–4027.
[9] D. C. Gowda, P. Gupta, E. A. Davidson, J. Biol. Chem. 1997, 272,
6428–6439.
[10] L. Schofield, M. C. Hewitt, K. Evans, M. Siomos, P. H. Seeberger,
Nature 2002, 418, 785–789.
[11] M. C. Hewitt, D. A. Snyder, P. H. Seeberger, J. Am. Chem. Soc.
2002, 124, 13434–13436.
[12] C. Murakata, T. Ogawa, Carbohydr. Res. 1992, 235, 95–114.
[13] D. K. Baeschlin, A. R. Chaperon, L. G. Green, M. G. Hahn, S. J.
Ince, S. V. Ley, Chem. Eur. J. 2000, 6, 172–186.
[14] U. E. Udodong, R. Madsen, C. Roberts, B. Fraser-Reid, J. Am.
Chem. Soc. 1993, 115, 7886–7887.
[15] A. S. Campbell, B. Fraser-Reid, J. Am. Chem. Soc. 1995, 117,
10387–10388.
[16] K. Pekari, R. R. Schmidt, J. Org. Chem. 2003, 68, 1295–1308.
[17] T. G. Mayer, B. Kratzer, R. R. Schmidt, Angew. Chem. 1994, 106,
2289–2293; Angew. Chem. Int. Ed. Engl. 1994, 33, 2177–2181.
[18] M. Martꢄn-Lomas, N. Khiar, S. Garcꢄa, J. L. Koessler, P. M. Nieto,
T. W. Rademacher, Chem. Eur. J. 2000, 6, 3608–3621.
[19] K. Pekari, D. Tailler, R. Weingart, R. R. Schmidt, J. Org. Chem.
2001, 66, 7432–7442.
[20] J. Xue, Z. Guo, J. Am. Chem. Soc. 2003, 125, 16334–16339.
[21] J. Lu, K. N. Jayaprakash, B. Fraser-Reid, Tetrahedron Lett. 2004, 45,
879–882.
1
and the corresponding disulfide (11 mg, 56%). H NMR (D2O): d=1.42–
1.78 (m, 10H), 2.83 (t, J=7.2 Hz, 2H), 3.34–3.49 (m, 4H), 3.61 (dd, J=
2.6, 10.0 Hz, 1H), 3.72–4.22 (m, 29H), 5.09 (brs, 1H), 5.16 (brs, 1H),
5.27 (d, J=1.3 Hz, 1H), 5.59 (d, J=3.8 Hz, 1H); 13C NMR (D2O): d=
24.8, 27.4, 28.5, 29.9, 38.5, 40.3, 54.2, 60.4, 61.2, 62.1, 62.2, 62.8, 65.1, 66.6,
66.7, 66.8, 66.9, 67.2, 70.1, 70.4, 70.6, 70.8, 71.4, 71.7, 72.2, 72.3, 72.5, 72.6,
73.0, 76.5, 76.7, 79.1, 95.6, 98.6, 102.1, 102.6; 31P NMR (D2O): d=1.52,
1.55; HRMS (ESI): m/z: calcd for C38H73N2O31P2S: 1147.3388; found
1147.3387 [M+H]+.
(a-d-Mannopyranosyl)-(1!2)-(6-O-(2-aminoethyl phosphono)a-d-man-
nopyranosyl)-(1!2)-(a-d-mannopyranosyl)-(1!6)-(a-d-mannopyrano-
syl)-(1!4)-(2-amino-2-deoxy-a-d-glucopyranosyl)-(1!6)-1-O-(6-thiohex-
yl phosphono)-d-myo-inositol (2a): Sodium methoxide (25 wt%, 0.1 mL,
0.43 mmol) was added to
a solution of phosphodiester 42 (36 mg,
0.01 mmol) in CH3OH/CH2Cl2 (1.5:0.5, 2 mL). After stirring for 5 h at
608C, the mixture was neutralized with Amberlite IR-120, filtered, and
evaporated under reduced pressure. The crude product was purified by
chromatography (CH3OH/CH2Cl2 gradient with 1% Et3N) to give the
diol. Ammonia (~20 mL) was condensed in a flame-dried three-necked
flask at ꢀ788C. Sodium metal was added portionwise until the solution
was dark blue. The obtained diol in THF (8 mL) was added via cannula,
followed by CH3OH (0.15 mL). The resultant dark blue solution was stir-
red at ꢀ788C for 30 min. Following disappearance of the blue color,
EtOH (2 mL) and AcOH (~0.5 mL) were added and ammonia was
blown off with a stream of Ar. Chromatography of the crude mixture on
Sephadex G-25 (EtOH/H2O 1:1), followed by dialysis and lyophilization
afforded a mixture (7.5 mg, 53%) of the target compound 2a and the
corresponding disulfide. 1H NMR (D2O): d=1.38–1.72 (m, 10H), 2.74 (t,
J=7.2 Hz, 2H), 3.34–4.21 (m, 40H), 5.02 (brs, 1H), 5.06 (brs, 1H), 5.20
(brs, 1H), 5.26 (brs, 1H), 5.52 (d, J=3.9 Hz, 1H); 13C NMR (D2O): d=
25.0, 27.5, 28.6, 30.1, 38.5, 61.2, 61.3, 64.9, 66.7, 66.9, 67.1, 67.2, 70.1, 70.3,
70.5, 70.6, 70.8, 71.5, 72.5, 73.1, 73.6, 73.7, 76.0, 78.6, 79.2, 98.7, 101.0,
102.4; 31P NMR (D2O): d=1.25, 1.32; MS (ESI): m/z: calcd for
C44H83N2O36P2S: 1309; found 1309 [M+H]+.
[22] J. Lu, K. N. Jayaprakash, U. Schlueter, B. Fraser-Reid, J. Am. Chem.
Soc. 2004, 126, 7540–7547.
[23] P. H. Seeberger, R. R. Soucy, Y. U. Kwon, D. A. Snyder, T. Kanemit-
su, Chem. Commun. 2004, 1706–1707.
[24] J. Stawinski, A. Kraszewski, Acc. Chem. Res. 2002, 35, 952–960.
[25] T. Ogawa, H. Yamamoto, Carbohydr. Res. 1985, 137, 79–88.
[26] I. Lindh, J. Stawinski, J. Org. Chem. 1989, 54, 1338–1342.
[27] W. Bannwarth, E. Kꢁng, T. Vorherr, Bioorg. Med. Chem. Lett. 1996,
6, 2141–2146.
[28] L. Heng, J. Ning, F. Kong, Carbohydr. Res. 2001, 331, 431–437.
[29] N. E. Byramova, M. V. Ovchinnikov, L. V. Backinowsky, N. K. Ko-
chetkov, Carbohydr. Res. 1983, 124, C8–C11.
[30] S. Josephson, D. R. Bundle, J. Chem. Soc. Perkin Trans. 1 1980, 297–
301.
[31] T. Oriyama, Y. Kobayashi, K. Noda, Synlett 1998, 1047–1048.
[32] D. M. Ratner, E. W. Adams, J. Su, B. R. OꢀKeefe, M. Mrksich, P. H.
Seeberger, ChemBioChem 2004, 5, 379–383.
Received: September 13, 2004
Published online: February 24, 2005
2504
ꢂ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
Chem. Eur. J. 2005, 11, 2493 – 2504