Synthesis of sialyl Lewis x mimetics as selectin inhibitors by enzymatic aldol condensation reactions

Article abstract of DOI:10.1016/S0968-0896(98)00242-9

Several D-mannosyl phosphate/phosphonate derivatives have been enzymatically prepared as sialyl Lewis x tetrasaccharide mimics, which showed strong-to-moderate inhibition against E-, P-, and L-selectins. The synthesis of these mimics is very straightforward; mannosyl aldehyde derivatives are condensed with dihydroxyacetone phosphate (DHAP) in the presence of a DHAP-dependent aldolase to provide mannosyl phosphates. Copyright (C) 1999 Elsevier Science Ltd.

Full text of DOI:10.1016/S0968-0896(98)00242-9

Bioorganic & Medicinal Chemistry 7 (1999) 425±433
Synthesis of Sialyl Lewis x Mimetics as Selectin Inhibitors by
Enzymatic Aldol Condensation Reactions
Chun-Cheng Lin,a Francisco Morõs-Varas,a Gabriel Weitz-Schmidtb
and Chi-Huey Wonga,*
aDepartment of Chemistry and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road,
La Jolla, CA 92037, USA
bNovartis Pharma AG, CH-4002 Basel, Switzerland
Received 4 August 1998; accepted 16 October 1998
AbstractÐSeveral d-mannosyl phosphate/phosphonate derivatives have been enzymatically prepared as sialyl Lewis x tetra-
saccharide mimics, which showed strong-to-moderate inhibition against E-, P-, and L-selectins. The synthesis of these mimics is
very straightforward; mannosyl aldehyde derivatives are condensed with dihydroxyacetone phosphate (DHAP) in the presence of a
DHAP-dependent aldolase to provide mannosyl phosphates. # 1999 Elsevier Science Ltd. All rights reserved.
Introduction
The bound conformation of SLex with selectins9 and the
functional groups essential for recognition by selectins
have been determined, including the carboxylate group
of the NeuAc moiety, the 2-, 3- and 4-hydroxyl groups
of the l-fucose moiety and the 4- and 6-hydroxyl groups
of the d-galactose moiety,10 as shown in Figure 1. This
recognition model provides useful information for the
design of SLex mimics.8 In addition, the presence of a
phosphate group in sugar derivatives was reported to be
bene®cial for inhibition of selectin binding.11
The discovery that the in¯ammatory response is trig-
gered by a highly selective carbohydrate±protein inter-
action has led to an intensive search for compounds to
block the interaction.1 The initial step of this carbohy-
drate-mediated biological process is the rolling adhesion
of the leukocytes to the vascular endothelium in the
early stage of leukocyte migration to the site of in¯am-
mation or tissue injury.2 The adhesion process involves
the interaction of sialyl Lewis x (SLex, Fig. 1), a term-
inal tetrasaccharide of glycoproteins and glycolipids,
with E-, P-, and L-selectins.3 Several sialylated and sul-
fated Lewis a or Lewis x are also ligands for E-, P-, and
L-selectins.4 Inhibition of the SLex/selectin interaction
has been reported to be an e€ective strategy for the
treatment of certain in¯ammatory diseases such as
reperfusion injury and heart attack.5 Although the
synthesis of SLex on large scale has been developed
for clinical evaluation,6 the binding anity of this
natural saccharide to the selectins is relatively weak
(IC50ꢀ0.5 mM against E-selectin) and can only be used
in its injectable form for acute symptoms as it has low
oral availability due to its low lipophilicity and labile
glycosidic linkages.7 Therefore, the development of SLex
mimetics with higher anity for the receptors, better
oral activity and higher stability against glycosidases7
has become a subject of current interest.8
Results and Discussion
In our preliminary work,12 we have reported that man-
nosyl phosphates 1 and 2 are good inhibitors of P- and
L-selectins. Molecular modeling showed that both 1 and
2 overlap well with the active conformations of SLex.
Here, we present the detailed synthesis of 1 and 2
and related structures using enzymatic aldol condensa-
tion, and analysis of those structures as inhibitors of the
three selectins. As shown in Figure 1, O- and C-man-
nosyl aldehydes were chosen as aldolase substrates
because d-mannose has been successfully used as the
l-fucose equivalent in the design of SLex mimetics.13 The
aldol condensation of the aldehyde with dihydroxy-
acetone phosphate (DHAP) and the corresponding
phosphonate (C-DHAP) using di€erent DHAP-depen-
dent aldolases generates two hydroxyl groups which we
postulate to mimic the 4- and 6-hydroxy groups of
the galactose moiety, and the phosphate/phosphonate
group which mimics the carboxylate negative charge.
This strategy creates two new stereogenic centers for use
*Corresponding author. Tel.: +1 619 784-2487; fax: +1 619 784-2409;
e-mail: wong@scripps.edu
0968-0896/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved.
PII: S0968-0896(98)00242-9

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C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
Figure 1. A model showing the structure and functional groups of SLex interacting with E- ( ), P- (*) and L-selectin ( ). Both E- and P-selectins
bind SLex in a similar manner with the carboxylate of NeuAc pointing behind the plane. L-selectin recognized the free form of SLex, with the
NeuAc-CO2H pointing above the plane as indicated in this ®gure.
to screen for the best mimic of the galactose residue and
is ¯exible enough to furnish a number of derivatives
while keeping the other essential groups in appropriate
spatial distance and orientation (see 3±7, Fig. 2). In
addition, the 6-position of the sugar moiety can be
changed to hydrophobic functional groups which are
expected to increase the binding activity with E- and P-
selectin.12,14
hydrogen bonding interaction between the 6-OH group
and E-selectin (Table 1).
The synthesis of the O-mannosyl aldehyde is shown in
Scheme 1. The anomeric center of mannose was pro-
tected as an allyl group (compound 8) and subsequent
ozonolysis gave aldehyde 9, which was detected as its
hydrate form by NMR. Compound 9 was condensed
with DHAP using RhaA and FucA, respectively, to
give compounds 3 and 4. The phosphate products were
isolated as barium salts. There was no requirement for
any chromatographic separation in the puri®cation
procedure. The barium chloride solution (4 equiv) was
added to the enzymatic reaction mixture which con-
tained inorganic phosphate (from DHAP preparation),
sulfate (from aldolase), organic phosphate (desired
product), and other neutral species (starting material).
After precipitation to remove most of inorganic phos-
phate, the supernatant was treated with 2 volumes of
acetone to precipitate out the organic phosphate, leav-
ing the neutral compounds in solution. Then, the
organic phosphate barium salt was acidi®ed by Dowex
50 to pH 2 and the resulting solution was neutralized to
pH 7 by 1 N NaOH to give the desired phosphate
mimetic. In order to obtain the 6-azido phosphate 5,
the primary hydroxyl group of compound 8 was con-
verted to the azide group. Tosylation of the primary
hydroxyl group of 8 followed by azide displacement
gave compound 10. Similarly, ozonolysis of compound
10 followed by coupling with DHAP a€orded com-
pound 5.
The biological activities of compounds 3±7 were eval-
uated as inhibitors of E-, P-, and L-selectins using the
procedure described previously.15 The IC50 values are
shown in Table 1. For O-glycoside mimetics, the rabbit
muscle FDP aldolase (RAMA) product 1 is a better
inhibitor than the rhamnulose 1-phosphate aldolase
(RhaA) product 3 and fuculose rhamnulose 1-phos-
phate aldolase (FucA) product 4. When comparing
compounds 1 and 2, the O-glycoside mimetic is more
active than the C-glycoside mimetic. This remarkable
enhancement of inhibition may be due to some
additional interactions of the aglycon group with some
unidenti®ed groups of P- and L-selectins (e.g. the elec-
trophilic carbonyl group with the lysine-NH2 group).
However, when the phosphate group was changed to
the phosphonate group, compound 7, the activity
decreased, perhaps due to the decrease in polarity,
resulting in a weaker interaction with the protein. The
inhibition activity also decreased when a 6-amide
group, compound 6, is present. This lower activity may
result from the drastic change of the structure through
the amide bond formation or from the loss of a

C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
427
Figure 2. Mannosyl phosphate/phosphonate SLex mimetics.
Scheme 2 illustrates the preparation of the enzymati-
cally generated 6-amide C-glycoside phosphate mimetic.
The benzyl protecting group of the primary hydroxy
group of compound 12 was changed to the acetyl group
in an acetic anhydride solution containing 0.3%
H2SO4.16 Interestingly, this transformation can be done
in a one-pot reaction to form the C-glycoside 13 if acetic
anhydride was added to the reaction mixture of allyl
TMS and compound 12 before workup. As shown in
Scheme 2, hydrolysis of the acetyl group of compound
13 followed by Mitsunobu reaction yielded the azido
compound 1417 which was then reduced to amine 22
by triphenyl phospine.18 The free amine of 15 was cou-
pled with acetic anhydride, 3-phenylpropionic acid
and stearic acid, respectively, to give compounds 16±18.
Osmium mediated dihydroxylation of the ole®n and
periodate cleavage of the diol followed by debenzyla-
tion to give the aldehydes in the hydrate form, com-
pounds 19±21. RAMA was used to catalyze the
condensation of DHAP and 6-NAc aldehyde 19 to
produce phosphate mimetic 6. Because of the low water
solubility of compounds 20 and 21, no aldol codensa-
tion products were found.
The C-glycosidic bond is stable against glycosidases in
vitro. However, the primary phosphate may be labile in
vivo to a number of phosphatases. For this reason, it is
highly desirable to prepare phosphate analogues stable
under biological conditions. Interestingly, the phospho-
nate analogue of DHAP, namely 4-hydroxy-3-oxobu-
tylphosphonic acid 25, is a donor substrate for DHAP
dependent aldolases. The synthesis of compound 25 is
shown in Scheme 3. The hydroxy group of glycidol 22
was protected as TBDMS and the resulting epoxide was
then opened by dimethyl methyl phosphonate and BuLi
to give compound 23, which was then oxidized to com-
pound 24. The methoxyl and TBDMS protecting
groups of compound 24 were deprotected by TMSBr
followed by neutralization with NaOH to pH 7.0 to
yield the sodium salt form of compound 25. Condensa-
tion of 25 with 26 gave compound 7. Though C-DHAP
is a poor substrate for RAMA (it took approximately
Table 1. IC50 (mM) values in selectin inhibitiona
1
2
3
4
5
6
7
SLex
E-
P-
L-
100
0.6
95
800
5
40
1500
140
270
160 inactive
320
200
3000
inactive
NDc
3300
900
2230
500 (720)b
>3000 (8000)b
NDc
1300 (3900)b
aDetermined in a cell-free assay (ref 15) based on the polymeric SLea interaction with a microtiter plate coated selectin. The values represent the
average of three measurements, with‹10% error.
bThe number is taken from the NMR study (ref 9a).
cNot determined.

428
C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
Scheme 1. Conditions: (a) allyl alcohol, cat. CSA, 90 ꢁC, overnight, 80%; (b) (i) O3, CH3Cl/MeOH=4/1, 78 ꢁC; (ii) PPh3, rt, 72%; (c) pH 6.7,
DHAP, RhaA, 31%; (d) pH 6.7, DHAP, FucA, 30%; (e) TsCl, Py, 0 ꢁC, 4 h, 62%; (f) NaN3, DMF, 60 ꢁC, 5 h, 54%; (g) pH 6.7, DHAP, FDPA,
30%.
Scheme 2. Conditions: (a) (i) Allyl TMS, TMSOTf, CH3CN, 0 ꢁC; (ii) Ac2O, 83%; (b) (i) NaOMe MeOH, 97%; (ii) DEAD, PPh3, N3P(O)(OPh)2,
88%; (c) PPh3, H2O, benzene, 82%; (d) EDC, HOBT, Acids, CH2Cl2, 82±97%; (e) (i) OsO4, MNO; (ii) NaIO4; (iii) H2, Pd/C, THF/H2O=1/1, 61±
67%; (f) DHAP, RAMA, pH 6.7, 32%.

C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
429
Scheme 3. Conditions: (a) TBDMSCI, imidazol, CH2Cl2, 91%; (b) MeP(O)(OMe)2, BuLi, Bf3 OEt2, THF, 78 ꢁC, 61%; (c) Dess±Martin reagent,
CH2Cl2, 68%; (d) (i) TMSBr, CH2Cl2; (ii) NaOH to pH 7.0, 75%; (e) DHAP, RAMA, pH 6.7, 7 days, 25%.
one week for the starting phosphonate to be consumed),
the phosphonate product can be prepared for inhibition
analysis. Although the two new stereogenic centers
generated in the aldolase reactions have not been deter-
mined with regard to their absolute con®gurations, the
stereospeci®cities of these aldolase reactions are
assumed to be the same as described previously.12
ꢀ-O-Allyl-D mannopyranoside 8. d-Mannose (1.5 g,
8.3 mmol) was added to 10 mL of allyl alcohol together
with a catalytic amount (10 mg) of camphorsulfonic
acid. The mixture was heated to 90 ꢁC overnight, then
the allyl alcohol was evaporated in vacuum. The residue
was puri®ed by ¯ash chromatography (EtOAc/MeOH,
6/1 then 4/1) to give the desired product (80% yield):
13C NMR (125 MHz, CD3OD) d 136.3, 118.3, 101.5,
75.5, 73.5, 73.0, 69.7, 69.4, 64.7.
Conclusion
Formylmethyl-ꢀ-O-mannopyranoside 9. A solution of
compound 8 (482 mg, 2.2 mmol) and catalytic amount
of NaHCO3 (10 mg) in CH2Cl2/MeOH (4/1, 40 mL) was
cooled to 78 ꢁC. O3 was bubbled through the solution
until a blue color was observed (10 min) then N2 was
bubbled through the solution until it became colorless.
Triphenylphosphine (577 mg, 6.6 mmol) was added and
the mixture was warmed to rt and stirred overnight.
After ®ltration, the solution was extracted with water
and the aqueous layer was evaporated under reduced
pressure. The residue showed only one compound (9,
72%) as dihydrate form: 13C NMR (125 MHz, D2O) d
100.1, 88.2, 72.7, 70.4, 70.0, 69.8, 66.7, 60.9.7.
In brief, this study describes a concise synthesis method
to prepare SLex mimetics. The results show that of the
three DHAP-dependant aldolases investigated, RAMA
generated the desired aglycon con®guration. Work is in
progress to investigate the mechanisms of binding to
selectins and to prepare a stable version of 1.
Experimental
General procedures
1H and 13C NMR spectra were recorded either on a
AMX-400 or AMX-500 spectrometer. Coupling con-
stants were measured in Hertz (Hz). High-resolution
mass spectra (HRMS) were obtained on a VG ZAB-
ZSE Mass Spectrometer using fast atom bombardment
(FAB) method in a m-nitrobenzylalcohol (NBA) matrix
doped with NaI or CsI. Column chromatography was
performed on Merck Kieselgel 60 (230±400 mesh).
Analytical thin-layer chromatography was performed
using precoated glass-backed plates (Merck Kieselgel
F254) and visualized by cerium phosphomolybdate or
ninhydrin. Diethyl ether and THF were distilled from
sodium-benzophenone ketyl, dichloromethane from
calcium hydride, toluene from sodium, and methanol
from magnesium. Other solvents and reagents were
puri®ed by standard procedures if necessary. Com-
pounds 1 and 2 were prepared according to the proce-
dure described previously.12
Compound 3. Compound 9 (330 mg, 1.5 mmol) and
DHAP (0.5 mmol) were dissolved in Tris bu€er (50 mM,
pH 7.4, 10 mL). The solution was adjusted to pH 6.7 by
adding 1 N NaOH and then 50 U of RhaA (from
Boehringer Mannheim) was added. The reaction mix-
ture was shook under N2 at rt. The progress of the
reaction was followed by DHAP consumption (assay by
glycerol phosphate dehydrogenase in the presence of
NADH) until >90% of the DHAP had been consumed
(about 14 h). The reaction mixture was adjusted to pH
.
7.5 and BaCl2 H2O (1.0 M, 2 mmol) was added slowly.
The cloudy mixture was kept at 4 ꢁC for 1 h and the
precipitates were removed by centrifugation. To the
supernatant, 2 volumes of acetone were added and the
mixture was stored at 4 ꢁC for 2 h. The precipitates were
collected by centrifugation and the supernatant was

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C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
discarded. The pellet was treated with Dowex-50 H+ to
pH 2 (the solid was dissolved) and the resin was ®ltered
o€. The ®ltrate was adjusted to pH 7.0±7.5 by adding
0.2 N NaOH. Lyophilization yielded compound 3
(400 MHz, D2O) d 4.80 (d, J=1.7 Hz, 1H), 4.70 (dd,
J=18.0, 6.3 Hz, 1H), 4.58 (dd, J=19.6, 6.3 Hz, 1H), 4.53
(d, J=3.0 Hz, 1H), 4.30±4.26 (m, 1H), 4.0±3.5 (m, 8H);
13C NMR (100 MHz, D2O) d 217.8, 102.6, 78.3, 77.9,
74.1, 72.5, 72.3, 70.5, 69.9 (d, 2JC-P=3.8 Hz), 65.1, 53.7.
1
(133 mg, 31%) as a white powder: H NMR (500 MHz,
D2O) d 4.72 (br, 1H), 4.67 (dd, J=20.5, 5.5 Hz, 1H),
4.61 (dd, J=20.5, 5.5 Hz, 1H), 4.53 (d, J=2.5 Hz, 1H),
4.31±4.29 (m, 1H), 3.94±3.54 (m, 8H); 13C NMR
(125 MHz, CDCl3) d 211.5, 100.5, 76.2, 73.2, 71.6, 70.3,
70.1, 68.3, 66.9, 66.1 (2Jc,p=5.0 Hz), 61.1.
Compound 13. A solution of methyl 2,3,4,6-tetra-O-
benzyl-a-d-mannopyranoside (11.2 g, 20.3 mmol) in
32 mL of dry MeCN was cooled to 0 ꢁC under N2.
Allyltrimethylsiane (6.5 mL, 40.5 mmol) and tri-
methylsilyl tri¯ate (1.9/mL, 10.2 mmol) were added. The
solution was stirred for 20 h at 0 ꢁC. Acetic anhydride
(8 mL, 80 mmol) was added and the resulting mixture
was stirred for 30 min at rt. The deep orange solution
was diluted with 130 mL of CH2Cl2 and quenched with
70 mL of saturated NaHCO3 solution. The aqueous
layer was washed twice with 30 mL of CH2Cl2. The
organic layers were combined and then dried over
MgSO4. The solvent was removed in vacuo, and the
residue was puri®ed by silica gel column chromato-
graphy (hexane/EtOAc, 9/1) to obtain compound 13
Compound 4. Compound 4 was synthesized similarly as
described in the synthesis of compound 3: 1H NMR
(500 MHz, D2O) d 4.76 (d, J=1.6 Hz, 1H), 4.64 (dd,
J=19.3, 5.0 Hz, 1H), 4.61 (dd, J=19.3, 5.0 Hz, 1H),
4.51 (d, J=4.0 Hz, 1H), 4.30±4.27 (m, 1H), 3.91±3.46
(m, 8H); 13C NMR (125 MHz, CDCl3) d 208.9
(3Jc,p=15 Hz), 100.7, 76.8, 73.9, 71.0, 70.8, 70.7, 67.5,
66.5, 63.6 (2Jc,p=2.2 Hz), 61.8.
Compound 10. To a solution of compound 8 (4.57 g,
20.8 mmol) in dry pryridine (51 mL) at 0 ꢁC was added
tosyl chloride (5.15 g, 27.0 mmol) dissolved in CH2Cl2
(75 mL), and the reaction was monitored by TLC. After
4 h, the starting material was consumed completely. The
reaction mixture was extracted with CH2Cl2 and washed
with 1 N HCl, saturated NaHCO3, and brine, and pur-
i®ed by ¯ash chromatography using EtOAc as eluent to
yield the desired compound (4.82 g, 62%): 1H NMR
(400 MHz, CDCl3) d 7.80 (d, J=8.2 Hz, 2H), 7.73 (d,
J=8.2 Hz, 2H), 5.93±5.83 (m, 1H), 5.27±5.22 (m, 1H),
5.17±5.14 (m, 1H), 4.68 (d, J=1.6 Hz, 1H), 4.33 (dd,
J=10.6, 1.8 Hz, 1H), 4.14 (dd, J=10.6, 7.0 Hz, 1H),
4.08 (ddt, J=12.1, 5.1, 1.5 Hz, 1H), 3.90 (ddt, J=12.1,
6.0, 1.3 Hz, 1H), 3.76 (dd, J=3.3, 1.6 Hz, 1H), 3.67±3.61
(m, 2H), 3.49 (t, J=9.6 Hz, 1H), 2.45 (s, 3H); 13C NMR
(100 MHz, CDCl3) d 135.6, 131.3, 129.5, 117.8, 101.3,
72.8, 72.6, 72.2, 71.7, 69.3, 68.5, 21.9; HRMS calcd for
C16H22O8NaS (M+Na): 397.0933, found 397.0945.
1
(8.7 g, 83 %, a/b>15/1) as a light yellow oil: H NMR
(500 MHz, CDCl3) d 7.35±7.28 (m, 15H), 5.72 (dddd,
J=17.0, 10.3, 6.9, 6.9 Hz, 1H), 5.04±5.00 (m, 2H), 4.75
(d, J=11.2 Hz, 1H), 4.63±4.53 (m, 5H), 4.39 (dd,
J=11.6, 6.4 Hz, 1H), 4.25 (dd, J=11.6, 2.8 Hz, 1H),
4.09±4.06 (m, 1H), 3.83±3.75 (m, 3H), 3.62 (dd, J=4.4,
2.7 Hz, 1H), 2.38±2.27 (m, 2H), 2.05 (s, 3H); 13C NMR
(125 MHz, CDCl3) d 170.9, 138.1, 138.0, 134.0, 128.6,
128.5, 128.4, 128.4, 128.3, 128.3, 128.0, 127.9, 127.9,
127.8, 127.8, 127.7, 117.3, 77.0, 75.0, 74.8, 74.0, 72.3,
72.2, 72.1, 71.5, 63.2, 34.4, 20.9; HRMS calcd for
C32H36O6Cs (M+Cs): 649.1566, found 649.1589.
Compound 14. A solution of compound 13 (5.3 g,
10.3 mmol) and NaOMe (0.23 g, 4.3 mmol) in 50 mL
MeOH was stirred at rt for 1 h. The solvent was evapo-
rated under reduced pressure, and the residue was pur-
i®ed by silica gel column chromatography (hexane/
EtOAc, 1/1) to a€ord the title compound (4.7 g, 97%) as
1
To a solution of the above compound (1.59 g, 4.3 mmol)
in DMF was added 15 equiv of NaN3 (4.14 g,
63.8 mmol) and this mixture was heated to 60 ꢁC for
overnight. The solvent was removed in vacuo, and the
residue chromatographed on SiO2 using EtOAc as elu-
ent to yield compound 10 (557 mg, 54%): 1H NMR
(400 MHz, CDCl3) d 5.94±5.87 (m, 1H), 5.33±5.30 (m,
1H), 5.23±5.20 (m, 1H) 4.90 (br, 1H), 4.24±4.20 (m, 1H),
4.06±4.01 (m, 1H), 3.84±3.80 (m, 1H), 3.78±3.74 (m,
1H), 3.71 (d, J=5.3, 3.7 Hz, 1H), 3.69±3.68 (m, 1H),
3.56±3.50 (m, 2H); 13C NMR (100 MHz, CDCl3) d
133.4, 117.7, 98.8, 71.7, 71.5, 70.6, 68.6, 68.1, 51.5.
a light yellow oil: H NMR (500 MHz, CDCl3) d 7.35±
7.29 (m, 15H), 5.68 (dddd, J=17.0, 10.2, 7.0, 7.0 Hz,
1H), 5.05±5.00 (m, 2H), 4.82 (d, J=11.1 Hz, 1H), 4.66
(d, J=11.1 Hz, 1H), 4.63 (d, J=11.1 Hz, 2H), 4.61 (d,
J=11.9 Hz, 1H), 4.57 (d, J=11.9 Hz, 1H), 4.03 (ddd,
J=9.2, 6.3, 3.5 Hz, 1H), 3.86±3.77 (m, 3H), 3.72 (ddd,
J=11.5, 6.8, 3.2 Hz, 1H), 3.64±3.59 (m, 2H), 2.39±2.33
(m, 1H), 2.25±2.20 (m, 1H), 2.03 (t, J=7.0 Hz, 1H); 13C
NMR (125 MHz, CDCl3) d 138.2, 133.8, 128.5, 128.4,
128.4, 128.3, 128.0, 128.0, 127.8, 127.8, 127.7, 117.6,
78.0, 75.3, 75.3, 74.5, 73.9, 73.5, 72.2, 72.0, 62.2, 34.2;
HRMS calcd for C30H34O5Cs (M+Cs): 607.1461,
found 607.1473.
Compound 11. Compound 11 was synthesized similarly
1
as described in the synthesis of compound 9: H NMR
To a solution of the above compound (3.2 g, 6.4 mmol)
in THF (14 mL) at 0 ꢁC was added DEAD (1.0 mL,
6.4 mmol) and PPh3 (1.74 g, 6.4 mmol) successively, and
the mixture was stirred for 20 min at 0 ꢁC. Diphenyl-
phosphoryl azide (1.4 mL, 6.4 mmol) was then added
dropwise and the resulting mixture was stirred at rt
overnight. The solvent was evaporated under reduced
pressure, and the residue was puri®ed by silica gel
column chromatography (hexane/EtOAc, 4/1) to yield
(400 MHz, D2O) d 5.20±5.17 (m, 1H), 4.87 (br, 1H),
3.98±3.96 (m, 1H), 3.82±3.75 (m, 2H), 3.70±3.61 (m,
3H), 3.58±3.52 (m, 1H), 3.52±3.47 (m, 1H); 13C NMR
(100 MHz, D2O) d 102.8, 90.6, 74.0, 72.7, 72.2, 69.8,
53.5, 41.1.
Compound 5. Compound 5 was synthesized similarly as
described in the synthesis of compound 3: 1H NMR

C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
431
compound 14 (3.0 g, 87.6%): 1H NMR (500 MHz,
CDCl3) d 7.36±7.27 (m, 15H), 5.73 (dddd, J=17.0, 10.2,
6.9, 6.9 Hz, 1H), 5.06±5.00 (m, 2H), 4.80 (d, J=11.3 Hz,
1H), 4.64 (d, J=12.2 Hz, 1H), 4.60 (d, J=12.2 Hz, 1H),
4.59 (d, J=12.1 Hz, 1H), 4.56 (d, J=11.3 Hz, 1H), 4.54
(d, J=12.1 Hz, 1H), 4.05 (ddd, J=8.3, 6.2, 4.1 Hz, 1H),
3.79±3.71 (m, 3H), 3.64±3.63 (m, 1H), 3.52 (dd, J=12.9,
6.8 Hz, 1H), 3.36 (dd, J=12.9, 3.1 Hz, 1H), 2.40±2.34
(m, 1H), 2.30±2.23 (m, 1H); 13C NMR (125 MHz,
CDCl3) d 138.1, 138.0, 133.8, 130.0, 128.5, 128.4, 128.4,
128.4, 128.0, 127.9, 127.8, 127.7, 126.1, 120.2, 120.2,
117.5, 77.4, 75.6, 74.9, 74.3, 73.4, 72.8, 72.1, 71.7, 51.2,
34.3; HRMS calcd for C30H33N3O4Cs (M+Cs):
632.1525, found 632.1540.
Compound 18. Compound 18 was synthesized similarly
as described in the synthesis of compound 17. 1H NMR
(500 MHz, CDCl3) d 7.36±7.26 (m, 15H), 5.84 (t,
J=4.6 Hz, 1H), 5.71 (dddd, J=17.1, 14.0, 7.0, 7.0 Hz,
1H), 5.06±5.01 (m, 2H), 4.73 (d, J=10.8 Hz, 1H), 4.65±
4.58 (m, 5H), 4.02±3.98 (m, 1H), 3.77 (dd, J=7.2,
2.9 Hz, 1H), 3.68±3.60 (m, 4H), 3.55 (dd, J=10.3,
5.9 Hz, 1H), 2.33 (t, J=6.9 Hz, 2H), 2.36±2.22 (m, 2H),
2.13±2.11 (m, 2H), 1.65±1.55 (m, 2H), 1.31±1.23 (m,
26H), 0.88 (t, J=6.8 Hz, 3H); 13C NMR (125 MHz,
CDCl3) d 173.1, 138.1, 138.0, 134.1, 128.4, 128.4, 128.3,
127.9, 127.8, 127.7, 117.6, 75.8, 75.4, 74.4, 72.8, 72.3,
71.9, 39.5, 36.8, 34.2, 33.9, 31.9, 29.7, 29.5, 29.4, 29.3,
29.1, 25.8, 24.7, 22.7, 14.1; HRMS calcd for C48H69NO5
(M+Cs): 872.4230, found 872.4246.
Compound 15. A mixture of compound 14 (1.7 g,
3.5 mmol) and PPh3 (1.83 mg, 7.0 mmol) was re¯uxed in
a mixture of benzene (20 mL) and water (0.13 mL) for
5 h. The reaction mixture was evaporated in vacuo and
the residue was applied to silica gel column chromato-
graphy (CHCl3/MeOH=20/1 then 10/1) to obtain
compound 15 (1.35 mg, 82 %): 1H NMR (500 MHz,
CDCl3) d 7.35±7.29 (m, 15H), 5.71 (dddd, J=17.0, 10.3,
6.9, 6.9 Hz, 1H), 5.04±5.00 (m, 2H), 4.80 (d, J=11.2 Hz,
1H), 4.64 (s, 2H), 4.60 (d, J=11.9 Hz, 1H), 4.58 (d,
J=11.2 Hz, 1H), 4.55 (d, J=11.9 Hz, 1H), 4.01 (ddd,
J=9.2, 6.0, 3.4 Hz, 1H), 3.77 (dd, J=7.7, 3.4 Hz, 1H),
3.68 (t, J=7.7 Hz, 1H), 3.63 (t, J=3.4 Hz, 1H), 3.48
(ddd, J=7.7, 7.7, 3.5 Hz, 1H), 2.94 (dd, J=13.3, 7.7 Hz,
1H), 2.89 (dd, J=13.3, 3.5 Hz, 1H), 2.39±2.33 (m, 1H),
2.27±2.21 (m, 1H), 1.41 (br, 2H); 13C NMR (125 MHz,
CDCl3) d 138.2, 134.2, 128.4, 128.4, 128.3, 128.1, 128.0,
127.8, 127.7, 127.7, 117.4, 78.0, 76.3, 75.4, 75.3, 74.3,
72.9, 72.1, 71.8, 43.0, 34.3; HRMS calcd for C30H36NO4
(M+H): 474.2644, found 474.2655.
Compound 19. To a solution of compound 15 (1.5 g,
3.2 mmol) in CH2Cl2 (10 mL) was added Ac2O (1.5 mL,
16.0 mmol), and the mixture was stirred for 2 h at rt.
The solvent was evaporated under reduced pressure,
and the residue was puri®ed by silica gel column chro-
matography (hexane/EtOAc, 2/1) to yield compound 16
(1.5 g, 91%).
To a solution of N-methylmorpholine N-oxide (0.35 g,
3.0 mmol) and 2.1 mL of 5/2 acetone/water was added a
solution of OsO4 in tert-butyl alcohol (0.33 mL, 2.5% w/
w), and the heterogeneous mixture was stirred vigor-
ously. Compound 16 (1.4 g, 2.7 mmol) was then added
dropwise. The biphasic mixture was stirred at rt over-
night and then quenched by addition of Na2S2O4 (0.1 g),
Florisil (1 g), and H2O (5 mL). This mixture was neu-
tralized to pH 7 with 1 N HCl and then concentrated.
The resulting aqueous suspension was acidi®ed to pH 1
with 1 N HCl and extracted with EtOAc (4Â15 mL).
The combined organic extracts were washed with brine,
dried (MgSO4), and concentrated to give diastereomeric
diols as white solid, which was used in the next step
without further puri®cation.
Compound 17. To a solution of amine 15 (1.11 g,
2.34 mmol) and 3-phenylpropionic acid (0.46 g,
3.0 mmol) in CH2Cl2 (10 mL) was added Et3N (0.3 mL),
HOBT (0.4 g, 3.0 mmol), and EDC (0.58 g, 3.0 mmol)
successively at 0 ꢁC. The solution was stirred at 0 ꢁC for
30 min and allowed to rise to room temperature within
6 h. The reaction mixture was evaporated under reduced
pressure and residue was dissolved in EtOAc (20 mL).
The EtOAc solution was washed with 1 N HCl, satu-
rated NaHCO3, and brine, successively. The organic
layer was dried over MgSO4 and evaporated in vacuo.
The residue was puri®ed by silica gel column chroma-
tography (hexane/EtOAc, 2/1) to yield compound 17
To a solution of the diols in 10 mL THF and NaIO4
(0.86 g, 4.0 mmol) was added in one portion. Water
(10 mL) was then added over 5 min to the stirred slurry.
After 1 h, THF was evaporated and the resulting slurry
was extracted with ethyl acetate. The organic layer was
then washed with brine, dried (MgSO4), and con-
centrated to give the crude aldehyde product which was
puri®ed by silica gel column chromatography (hexane/
EtOAc, 1/1) to give the aldehyde compound (1.2 g,
86%): 1H NMR (500 MHz, CDCl3) d 9.78 (s, 1H), 7.36±
7.29 (m, 15H), 6.72 (d, J=11.9 Hz, 1H), 4.53 (d,
J=11.5 Hz, 1H), 4.51 (d, J=12.5 Hz, 1H), 4.49 (d,
J=11.5 Hz, 1H), 4.48 (d, J=11.6 Hz, 1H), 4.48±4.44 (m,
1H), 4.40 (d, J=12.5 Hz, 1H), 4.37 (d, J=11.6 Hz, 1H),
3.87±3.85 (m, 1H), 3.83±3.82 (m, 1H), 3.80±3.77 (m,
1H), 3.67 (ddd, J=10.1 9.0, 3.9 Hz, 1H), 3.56 (dd,
J=9.0, 2.8 Hz, 1H), 3.51 (dd, J=3.9, 1.8 Hz, 1H), 2.98
(dd, J=18.5, 2.4 Hz, 1H), 2.66 (dd, J=18.5, 10.1 Hz,
1H), 2.03 (s, 3H); 13C NMR (125 MHz, CDCl3) d 200.7,
170.1, 137.4, 128.4, 128.4, 128.0, 127.9, 127.9, 127.7,
75.1, 74.8, 74.2, 72.9, 72.8, 72.1, 71.2, 62.6, 45.4, 37.0,
23.1; HRMS calcd for C31H35NO6Cs (M+Cs): 650.1519,
found 650.1533.
1
(1.38 g, 96.7%): H NMR (500 MHz, CDCl3) d 7.37±
7.25 (m, 18H), 7.19±7.16 (m, 2H), 5.77 (br, 1H), 5.67
(dddd, J=17.2, 10.2, 7.1, 7.1 Hz, 1H), 5.04±4.99 (m,
2H), 4.70 (d, J=10.9 Hz, 1H), 4.63 (d, J=12.0 Hz, 1H),
4.59 (d, J=12.2 Hz, 1H), 4.58 (d, J=12.0 Hz, 1H), 4.57
(d, J=12.2 Hz, 1H), 4.54 (d, J=10.9 Hz, 1H), 3.99±3.95
(m, 1H), 3.75 (dd, J=7.4, 3.0 Hz, 1H), 3.68 (t,
J=7.4 Hz, 1H), 3.63±3.51 (m, 4H), 2.93 (t, J=7.8 Hz,
2H), 2.44±2.39 (m, 2H), 2.33±2.27 (m, 1H), 2.25±2.17
(m, 1H); 13C NMR (125 MHz, CDCl3) d 176.6, 140.8,
137.9, 134.0, 128.4, 128.3, 128.2, 128.1, 127.8, 127.8,
127.7, 126.0, 117.4, 78.8, 75.7, 74.3, 72.2, 72.1, 71.8,
58.2, 39.5, 38.2, 34.0, 31.5; HRMS calcd for C39H44NO5
(M+H): 606.3219, found 606.3217.

432
C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
The above compound (0.83 g, 1.6 mmol) was dissolved
in a mixture of tetrahydrofuran/water (1/1) solution and
hydrogenated at 1 atm H2 in the presence of catalytic
amounts of Pd/C. After stirring at rt for 6 h, the reac-
tion mixture was ®ltered o€ using a Celite pad. The
solvent was removed under vacuum to give compound
19 (0.42 g, 98%) which was used in the next step without
further puri®cation. 13C NMR (125 MHz, D2O) d 175.2,
89.2, 75.7, 75.6, 72.8, 72.0, 71.2, 69.3, 41.1, 22.5.
Butyllithium (28.4 mmol, 11.4 mL of 2.5 M solution)
was added and the mixture was stirred for 15 min. A
solution of glycidyl-tert-butyldimethylsilyl ether (1.78 g,
9.5 mmol) in 10 mL of THF was then added to the
reaction mixture dropwise, followed by addition of
.
BF3 Et2O (4.8 ml, 37.9 mmol) and the mixture was
allowed to react for 2 h at 78 ꢁC. The reaction was
quenched by adding a saturated aqueous NH4Cl. The
reaction mixture was evaporated under reduced pres-
sure and the residue was dissolved in Et2O. The Et2O
solution was washed with 1 N HCl, saturated NaHCO3,
and brine, successively. The organic layer was dried
over MgSO4 and evaporated in vacuo. The residue was
then puri®ed by silica gel column chromatography
(MeOH/CHCl3, 5/95) to yield compound 24 (1.8 g,
Compound 20. Compound 20 was synthesized similarly
as described in the synthesis of compound 19: for the
1
intermediate aldehyde before hydrogenation H NMR
(500 MHz, CDCl3) d 9.74 (s, 1H), 7.36±7.15 (m, 20H),
6.67 (d, J=6.1 Hz, 1H), 4.53 (d, J=12.1 Hz, 1H), 4.52 (d,
J=11.9 Hz, 1H), 4.49 (d, J=12.1 Hz, 1H), 4.48 (d, J=
11.6 Hz, 1H), 4.43 (d, J=1.8 Hz, 1H), 4.39 (d, J=
11.9 Hz, 1H), 4.37 (d, J=11.6 Hz, 1H), 3.83±3.79 (m,
2H), 3.74 (dd, J=10.6, 2.9 Hz, 1H), 3.70±3.64 (m, 1H),
3.55 (dd, J=9.0, 2.9 Hz, 1H), 3.49 (dd, J=4.0, 1.8 Hz,
1H), 2.70±2.92 (m, 3H), 2.67±2.60 (m, 1H), 2.57±2.53 (m,
2H); 13C NMR (125 MHz, CDCl3) d 200.7, 172.2, 141.1,
140.2, 137.5, 128.5, 128.4, 128.1, 128.0, 127.8, 126.0, 75.2,
74.8, 74.2, 73.0, 72.8, 72.2, 71.3, 62.7, 45.4, 38.4, 37.0,
31.8; HRMS calcd for C38H41NO6Cs (M+Cs): 740.1988,
found 740.1992. For compound 20: 13C NMR (125 MHz,
D2O) d 176.8, 141.1, 129.5, 129.3, 129.2, 127.2, 89.1, 75.7,
75.4, 73.0, 72.8, 72.1, 71.9, 71.2, 71.1, 69.4, 69.3, 58.8,
41.0, 38.1, 32.1, 32.1, 30.6 (rotamers present in NMR).
1
61%): H NMR (500 MHz, CDCl3) d 3.74 (s, 3H), 3.71
(s, 3H), 3.65±3.62 (m, 1H), 3.60 (dd, J=9.7, 4.0 Hz,
1H), 3.42 (dd, J=9.7, 6.6 Hz, 1H), 2.67 (d, J=4.0 Hz,
1H), 2.04±1.60 (m, 4H), 0.87 (s, 9H), 0.05 (s, 6H); 13C
3
NMR (125 MHz, CDCl3) d 71.4 (d, JC-P=14.7 Hz),
66.7, 52.4 (d, JC-P=7.0 Hz), 25.8, 20.8 (d, JC-P=
2
1
142.1 Hz), 18.3, 5.4 (Â2); HRMS calcd for C12H30
O5PSi (M+H): 313.1600, found 313.1610.
Compound 24. Compound 23 (4.8 g, 15.3 mmol) was
dissolved in 150 mL of dry CH2Cl2 under argon atmo-
sphere at room temperature. Dess±Martin reagent (9.8 g,
23 mmol) was added to the solution and the mixture was
allowed to react for 1 h. 200 mL of Et2O was added
together with 7 equiv of sodium thiosulfate in saturated
NaHCO3 solution. After 30 min, the mixture was
washed with NaHCO3 and brine. The organic layer was
dried over MgSO4 and evaporated in vacuo. The residue
was then puri®ed by silica gel column chromatography
(EtOAc/Hex, 1/1) to yield compound 24 (3.2 g, 68%):
1H NMR (500 MHz, CDCl3) d 4.20 (s, 2H), 3.75 (s, 3H),
3.73 (s, 3H), 2.86±2.80 (m, 2H), 2.08±2.01 (m, 2H), 0.93
(s, 9H), 0.1 (s, 3H), 0.09 (s, 3H); 13C NMR (125 MHz,
Compound 6. Compound 6 was synthesized similarly as
described in the synthesis of compound 3: 1H NMR
(500 MHz, D2O) d 4.78 (dd, J=18.5, 7.7 Hz, 1H), 4.67
(dd, J=18.6, 7.7 Hz, 1H), 4.38 (d, J=2.1 Hz, 1H), 4.14
(dt, J=10.1, 2.4 Hz, 1H), 4.08±4.06 (m, 1H), 3.87±3.85
(m, 1H), 3.80±3.75 (m, 2H), 3.55±3.52 (m, 3H), 3.38±
3.34 (m, 1H), 2.04±1.98 (m, 1H), 2.00 (s, 3H), 1.69 (ddd,
J=14.2, 10.5, 3.5 Hz, 1H); 13C NMR (125 MHz,
CDCl3) d 175.4, 163.6, 78.8, 75.5, 72.7, 72.5, 71.3, 69.5,
68.5, 47.5, 41.2, 31.4, 22.7.
CDCl3) d 208.6 (d, 3JC-P=14.3 Hz), 69.1, 52.4 (d, 2JC-P
6.6 Hz), 31.4, 25.7, 17.8 (d, JC-P= 145.0 Hz), 5.6.
=
1
Compound 23. To a solution of glycidol 22 (10 g,
0.128 mol) in 108 mL of dry CH2Cl2 was added imidazole
(7.85 g, 0.115 mol). The reaction mixture was stirred at
0 ꢁC for 5 min and then TBDMSCl (17.4 g, 0.115 mol)
was added in one portion. The solution was stirred at
0 ꢁC for 1 h and allowed to rise to room temperature
within 4 h. The reaction mixture was evaporated under
reduced pressure and the residue was dissolved in
EtOAc (50 mL). The EtOAc solution was washed with 1
N HCl, saturated NaHCO3, and brine, successively. The
organic layer was dried over MgSO4 and evaporated in
vacuo. The residue was puri®ed by silica gel column
chromatography (hexane/EtOAc, 95/5) to yield glyci-
dyl-tert-butyldimethylsilyl ether (19.8 g, 91%): 1H NMR
(500 MHz, CDCl3) d 3.86 (dd, J=11.9, 3.1 Hz, 1H), 3.66
(dd, J=11.9, 4.8 Hz, 1H), 3.10±3.07 (m, 1H), 2.77 (dd,
J=5.1, 4.1 Hz, 1H), 2.64 (dd, J=5.1, 2.7 Hz, 1H), 0.9 (s,
9H), 0.09 (s, 3H), 0.08 (s, 3H); 13C NMR (125 MHz,
CDCl3) d 63.7, 52.4, 44.5, 25.8, 5.3, 5.4.
Compound 25. To a solution of 24 (3.0 g, 9.6 mmol) in
20 mL of dry CH2Cl2 was added 20 mmol of TMSBr
(2.6 mL) dropwise under argon atmosphere at rt. The
reaction mixture was stirred at rt for 30 min. The sol-
vent was then evaporated and 10 mL of distilled water
was added. After 30 min the mixture was extracted with
AcOEt, the aqueous layer which contained the desired
product was adjusted to pH 7.0 and evaporated to
obtain 1.5 g of the product as sodium salt (75% yield).
Further puri®cation was carried out by passing the
compound through a Dowex 1Â8 (HCO3 form) col-
umn and washing with water and eluting with 300 mM
of triethylammonium bicarbonate bu€er. The fractions
containing the product were pooled and passed through
a column of Dowex 50W-X2 Na+ form and lyophilized:
1H NMR (500 MHz, D2O) d 4.20 (s, 2H), 2.45 (m, 2H),
1.60 (m, 2H); 13C NMR (125 MHz, CDCl3) d 214.8 (d,
3JC-P=14 Hz), 68.3, 56.3 (d, 2JC-P= 6 Hz), 33.3, 21.9 (d,
1JC-P=135.0 Hz).
A solution of methyl dimethylphosphonate (3.1 mL,
28.4 mmol) in 32 ml of THF was cooled to 78 ꢁC.
Compound 7. Compound 7 was obtained similarly as
described in the synthesis of compound 3: 1H NMR

C.-C. Lin et al. / Bioorg. Med. Chem. 7 (1999) 425±433
433
(500 MHz, D2O) d 4.39 (d, J=2.0 Hz, 1H), 4.29 (ddd,
J=10.0, 3.0, 2.0 Hz, 1H), 4.15 (ddd, J=11.0, 3.5, 3.3
Hz, 1H), 3.79 (dd, J=12.3, 4.4 Hz, 1H), 3.73 (dd,
J=3.3, 2.3 Hz, 1H), 3.65 (dd, J=9.4, 2.3 Hz, 1H), 3.58
(dd, J=12.3, 5.8 Hz, 1H), 3.49 (t, J=9.4 Hz, 1H), 3.42
(ddd, J=9.4, 5.8, 4.4 Hz, 1H), 2.82 (m, 2H), 2.10 (ddd,
J=14.2, 11.0, 3.0 Hz, 1H), 1.75 (ddd, J=10.0, 3.0,
2.0 Hz, 1H), 1.60 (m, 2H); 13C NMR (125 MHz, CDCl3)
D. E.; Connor, J. R.; Griswold, D. E.; Vasant Kumar; N.;
Kopple, K. D.; Carr, S. A.; Dalton, B. J.; Johanson, K. J.
Biol. Chem. 1994, 269, 23949
10. (a) Stahl, W.; Sprengard, U.; Kretzschmar, G.; Kunz, H.
Angew. Chem., Int. Ed. Engl. 1994, 33, 2096. (b) Ramphal, J.
Y.; Zheng, Z.-L.; Perez, C.; Walker, L. E.; DeFrees, S. A.;
Gaeta, F. C. A. J. Med. Chem. 1994, 37, 3459. (c) DeFrees, S.
A.; Kosch, W.; Way, W.; Paulson J. C., Sabesan, S.; Halcomb,
R. L.; Huang, D.-H.; Ichikawa, Y.; Wong, C.-H. J. Am.
Chem. Soc. 1995, 117, 60. (d) Brandley, B. K.; Kiso, M.;
Abbas, S.; Nikrad, P.; Srivastava, O.; Foxall, C.; Oda, Y.;
Hasegawa, A. Glycobiology 1993, 3, 633. (e) Tyrrell, D.;
James, P.; Rao, N.; Foxall, C.; Abbas, S.; Dasgupta, F.;
Nashed, M.; Hasegawa, A.; Kiso, M.; Asa, D.; Kidd, J.;
Brandley, B. K. Proc. Natl. Acad. Sci. USA 1991, 88, 10372.
(f) Nelson, R. M.; Dolish, S.; Aru€o, A.; Cecconi, O.; Bev-
ilacqua, M. P. J. Clin. Invest. 1993, 91, 1157. (g) Graves, B. J.;
Crowther, R. L.; Chandran, C.; Rumberger, J. M.; Li, S.;
Huang, K.-S.; Presky, D. H.; Familletti, P. C.; Wolitzky, B.
A.; Burns, D. K. Nature 1994, 367, 532. (h) Kogan, T. P.;
Revelle, B. M.; Tapp, S.; Scott, D.; Beck, P. J. J. Biol. Chem.
1995, 270, 14047.
11. (a) Imai, Y; Lasky, L. A.; Rosen, S. D. Glycobiology 1992,
2, 373. (b) Moor K. L.; Varki, A; McEver, R. P. J. Cell Biol.
1991, 112, 491. (c) Cecconi, O.; Nelson, R. M.; Robert, M. G.;
Hanasaki, K.; Mannori, G.; Shultz, C.; Ulich, T. R.; Aru€o,
A.; Bevilacqua, M. P. J. Biol. Chem. 1994, 269, 15060. (d)
Manning, D. D.; Bertozzi, C. R.; Rosen, S. D.; Kiessling, L.
L. Tetrahedron Lett. 1996, 37, 1953.
12. Wong, C.-H., Francisco M.-V., Hung, S.-C., Marron, T.-
G., Lin, C.-C., Gong, K. W.; Weitz-Schmidt, G. J. Am. Chem.
Soc. 1997, 119, 8152.
13. (a) Dupre, B.; Bui, H.; Scott, I. L.; Market, R. V.; Keller,
K. M.; Beck, P. J.; Kogan, T. P. Bioorg. Med. Chem. Lett.
1996, 6, 569. (b) Marron, T. G., Woltering, T. J.; Weitz-
Schmidt, G.; Wong, C.-H. Tetrahedron Lett. 1996, 37, 9037.
(c) Hiruma, K.; Kayimoto, T. Weitz-Schmidt, G.; Ollmann, I.;
Wong, C.-H. J. Am. Chem. Soc. 1996, 118, 9265.
14. (a) Ramphal, J. Y.; Hiroshige, M.; Lou, B.; Gaudino, J.
J.; Hayashi, M.; Chen, S. M.; Chiang, L. C.; Gaeta, F. C. A.;
DeFrees, S. A. J. Med. Chem. 1996, 39, 1357. (b) Hayashi, M.;
Tanaka, T.; Itoh, M.; Miyauchi, H. J. Org. Chem. 1996, 61,
2938.
15. Weitz-Schmidt, G.; Stokmaier, D.; Scheel, G.; Nifant'ev,
N. E.; Tuzikov, A. B.; Bovin, N. V. Ann. Biochem. 1996, 238,
184.
16. (a) Kobertz, W. R.; Bertozzi, C. R.; Bednarski, M. D. J.
Org. Chem. 1996, 61, 1895. (b) Lin, C.-C.; Shimazaki, M.;
Heck, M.-P.; Aoki, S.; Wang, R.; Kimura, T.; Ritzen, H.;
Takayama, S.; Wu, S.-H.; Weitz-Schmidt, G.; Wong, C.-H. J.
Am. Chem. Soc. 1996, 118, 6826.
3
d 213.8 (d, JC-P=15 Hz), 78.4, 76.9, 75.0, 71.9, 71.4,
67.7, 63.5, 61.9, 34.2, 32.5, 25.7 (d, JC-P=138.0 Hz).
1
Acknowledgements
The authors thank the NIH for ®nancial support (NIH
GM44154). F. M.-V. thanks the Ministerio de Educa-
cion y Ciencia (Spain) for a postdoctoral fellowship.
References and Notes
1. (a) Yarema, K. J.; Bertozii, C. R. Curr Opin. Chem. Biol.
1998, 2, 49. (b) Lowe, J. B.; Ward, P. A. J. Clin. Invest. 1997,
99, 822.
2. (a) Levy, D. E.; Tang, P. C.; Musser, J. H. Annu. Rep. Med.
Chem., 1994, 215. (b) Lasky, L. A. Science 1992, 258, 964.
3. (a) Phillips, M. L.; Nudelman, E.; Gaeta, F. C. A.; Perez,
M.; Singhal, A. K.; Hakomori, S. I.; Paulson, J. C. Science
1990, 250, 1130. (b) Walz, G.; Aru€o, A.; Kolanus, W.; Bev-
ilacqua, M. P.; Seed, B. Science 1990, 250, 1132. (c) Lowe, J.
B.; Stoolman, L. M.; Nair, R. P.; Larsen, R. D.; Berhend, T.
L.; Mark, R. M. Cell 1990, 63, 475. For reviews on the selec-
tin-carbohydrate interactions, see: (d) Lasky, L. A. Annu. Rev.
Biochem. 1995, 64, 113. (e) Springer, T. A. Cell 1994, 76, 301.
4. Rosen, S. D.; Bertozzi, C. R. Current Biology 1996, 6, 261.
5. (a) Buerke, M.; Weyrich, A. S.; Zheng, Z.; Gaeta, F. C. A.;
Forrest, M. J.; Lefer, A. M. J. Clin. Invest. 1994, 1140. (b)
Mulligan, M. S.; Paulson, J. C.; Frees, S. D.; Zheng, Z. L.;
Lowe, J. B.; Ward, P. A. Nature 1993, 364, 149. (c) Murohara,
T.; Margiotta, J.; Phillips, L. M.; Paulson, J. C.; DeFrees, S.;
Zalipsky, S.; Guo, L. S. S.; Lefer, A. M. Cardiovascular Res.
1995, 30, 965.
6. Ichikawa, Y.; Lin, Y.-C.; Dumas, D. P.; Shen, G.-J.; Gar-
cia-Junceda, E.; Williams, M. A.; Bayer, R.; Ketcham, C.;
Walker, L. E.; Paulson, J. C.; Wong, C.-H. J. Am. Chem. Soc.
1992, 114, 9283.
7. SLex is sensitive to a-fucosidase and neuraminidase.
8. Simanek, E. E.; McGarvey, G, J.; Jablonowski, J. A.;
Wong, C,-H. Chem. Rev. 1998, 98, 833.
9. (a) Poppe, L.; Brown, G. S.; Philo, J. S.; Nikrad, P. V.;
Shah, B. H. J. Am. Chem. Soc. 1997, 119, 1727. (b) Sche‚er,
K.; Ernst, B.; Katopodis, A.; Magnani, J. L.; Wang, W. T.;
Weisemann, R.; Peters, T. Angew. Chem., Int. Ed. Engl. 1995,
34, 1841. (c) Cooke, R. M.; Hale, R. S.; Lister, S. G.; Shah,
G.; Weir, M. P. Biochemistry 1994, 33, 10591. (d) Hensley, P.;
McDevitt, P. J.; Brooks, I.; Trill, J. J.; Feild, J. A.; McNulty,
17. (a) Mitsunobu, O. Synthesis 1981, 1. (b) Francisco M.-V.;
Qian, X.-H.; Wong, C.-H. J. Am. Chem. Soc. 1996, 118, 7647.
18. (a) Dong, Z.; Butcher Jr., J. A. Tetrahedron Lett. 1991, 32,
5291. (b) Greilich, U.; Zimmermann, P.; Jung, K. H.; Schmidt,
R. R. Liebigs Ann. Chem. 1993, 859.