Assembly and inhibitory activity of monovalent mannosides terminated with aromatic methyl esters: The effect of naphthyl groups

Article abstract of DOI:10.1016/j.carres.2017.03.020

A series of monovalent α-D-mannoside ligands terminated with aromatic methyl esters have been synthesized in excellent yields using the Cu(I) catalyzed azide-alkyne 1,3-dipolar cycloaddition (“click chemistry”). These mannosides were designed to have a unique aglycone moiety (tail) that combines a triazole ring attached to aromatic methyl esters via a six carbon alkyl chain. The mannose unit of these ligands was linked at the ortho, meta, and para positions of substituted methyl benzoates and 1-, 3-, and 6-substituted methyl 2-napthaoates. In hemagglutination assays, ligands (32A-38A) showed better inhibitory activities than the standard inhibitor, methyl α-D-mannopyranoside. Overall, the naphthyl-based mannoside ligand (37A) showed the best activity and therefore merits further development.

Full text of DOI:10.1016/j.carres.2017.03.020

Accepted Manuscript
Assembly and inhibitory activity of monovalent mannosides terminated with aromatic
methyl esters: The effect of naphthyl groups
Hussein Al-Mughaid, Raed M. Al-Zoubi, Maha Khazaaleh, T. Bruce Grindley
PII:
S0008-6215(17)30069-1
10.1016/j.carres.2017.03.020
CAR 7349
DOI:
Reference:
To appear in: Carbohydrate Research
Received Date: 26 January 2017
Revised Date: 13 March 2017
Accepted Date: 16 March 2017
Please cite this article as: H. Al-Mughaid, R.M. Al-Zoubi, M. Khazaaleh, T.B. Grindley, Assembly and
inhibitory activity of monovalent mannosides terminated with aromatic methyl esters: The effect of
naphthyl groups, Carbohydrate Research (2017), doi: 10.1016/j.carres.2017.03.020.
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ACCEPTED MANUSCRIPT
Head
Tail
α
-D-mannoside
OH
HO
HO
triazole
N
O
O
N
Aromatic
zone
HO
N
Alkyl chain
O

ACCEPTED MANUSCRIPT
Assembly and Inhibitory Activity of Monovalent Mannosides Terminated
with Aromatic Methyl Esters: The Effect of Naphthyl Groups
Hussein Al-Mughaida,b*, Raed M. Al-Zoubia, Maha Khazaaleha, and T. Bruce Grindleyb*
aDepartment of Chemistry, Jordan University of Science and Technology, PO Box 3030,
Irbid 22110, Jordan.
bDepartment of Chemistry, Dalhousie University, Halifax, NS, B3H 4J3, Canada
Head
Tail
α-D-mannoside
OH
O
HO
HO
HO
triazole
N
O
Aromatic
zone
N
N
Alkyl chain
O
Abtract: A series of monovalent α-D-mannoside ligands terminated with aromatic
methyl esters have been synthesized in excellent yields using the Cu(I) catalyzed azide-
alkyne 1,3-dipolar cycloaddition ("click chemistry"). These mannosides were designed to
have a unique aglycone moiety (tail) that combines a triazole ring attached to aromatic
methyl esters via a six carbon alkyl chain. The mannose unit of these ligands was linked
at the ortho, meta, and para positions of substituted methyl benzoates and 1-, 3-, and 6-
substituted methyl 2-napthaoates. In hemagglutination assays, ligands (32A-38A) showed
better inhibitory activities than the standard inhibitor, methyl α-D-mannopyranoside.
Overall, the naphthyl-based mannoside ligand (37A) showed the best activity and
therefore merits further development.
Key words: α-D-mannosides; click chemistry; FimH; hemagglutination.
*Corresponding Author: Hussein Al-Mughaid; Email: al-mughaid@just.edu.jo
Telephone: 962-2-7201000, ext-23587 Fax: 962-2-7201071
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1. Introduction
Urinary tract infections (UTIs), are one of the most common bacterial infections,
affecting millions of people around the world each year.1-3 (UTIs) are mainly caused by
strains of the gram negative uropathogenic bacteria, Escherichia coli (UPEC).4 The vast
majority of E. coli express Type 1 fimbriae or pili, which are hair-like protein structures
present on the cell surfaces. UPEC bind to the urinary tract endothelial surface through
the 200 to 500 fimbriae which extend from the surface of each bacterial cell. At the tip of
each pili there is an adhesin protein known as FimH, a lectin that uniquely interacts with
terminal α-D-mannopyranoside residues of the N-linked glycoprotein Uroplakin Ia
(UPIa) on the endothelial surface, enabling adherence and invasion of the host cell and at
the same time preventing the rapid clearance of E. coli from the UTI by the bulk flow of
urine.5 The carbohydrate recognition domain (CRD) of the FimH protein consists of
amino acids with hydrophilic side chains that can establish a network of hydrogen bonds
with the C2, C3, C4, and C6 hydroxyl groups of an α-D-mannopyranoside. It is now well
established that the entrance (tyrosine gate) to the mannose-binding pocket of FimH is
formed by two tyrosine residues (Tyr48 and Tyr137) and one isoleucine residue (Ile52)
which support hydrophobic contacts.6 Consequently, the introduction of an aromatic
moiety in the mannosyl tail (aglycon) can establish favorable π-π interactions with the
aromatic side chains of Tyr48, and Tyr137, thus enhancing the affinity of aromatic
mannosides relative to the alkyl ones.7-9 Crystal structures and docking studies of
biphenyl O- and C-glycosides of α-D-mannopyranose complexed with FimH revealed
that the hydrophobic rim formed by Tyr48, Tyr137, and Ile52 is not reached by the first
2

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phenyl ring, but the outer phenyl ring induces π-π interactions with the phenyl groups of
the tyrosines in the tyrosine gate, enhancing the affinity of α-D-mannoside ligands for
FimH.10-13
Recently, a number of monovalent mannose-based FimH antagonists with diverse
-mannoside,14 and multimeric versions,15-18 biphenyl
-mannosides,10 and their derivatives,19 indolinylphenyl and (aza)indolylphenyl α-
D-
mannosyl tails such as n-heptyl α-
D
α-
D
mannosides,20 thiazolylaminomannosides,21 squaric acid mannosides,22,23 mannosyl
trizoles,24 mannosyl ferrocenes,25 mannosylated N-arylsubstituted 3-hydroxypyridine-4-
ones,26 branched α- -mannosides,27 C-glycosides12 and others28-31 have been reported.
D
In addition, it has recently been suggested that orally administrated acid-resistant
mannopyranosides are medicines against Crohn’s disease.11,32-36
An overview of FimH antagonists designed so far revealed three classes: (i) α-D-
mannosides with an alkyl chain in the tail, (ii) α-D-mannosides with an aryl glycoside at
the start of the tail, (iii) α-D- mannosides with an extended planar glycoside starting the
tail. It becomes obvious that the nature of the mannosyl tail (aglycone: elongated alkyl,
substituted aromatic, and extended aromatic) plays a fundamental role in binding affinity,
and therefore, altering its structure might influence the inhibitory potency toward type 1
fimbriated E. coli.
The Cu(I)-catalyzed 1,3-dipolar cycloaddition between terminal alkynes and azides
(click chemistry) has proven to be a powerful tool in the synthesis of
neoglycoconjugates.37 Following our interest in using click chemistry for the synthesis of
mannoside ligands38, we present herein the assembly and the activity of a series of alkyl
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α-D
-mannosides each terminated with a different aryl methyl ester moiety prepared by
clicking a common propargyl mannoside onto a series of alkyl azide-modified aromatic
methyl esters. The positions of substitution of the aromatic methyl esters were
systematically varied and both phenyl and naphthyl cores were used to determine the best
geometry for mannose-FimH recognition. It is worth mentioning that the choice to
incorporate aromatic methyl esters in the mannosyl tail was based on recent finding that
phenolic mannosides having methyl esters in the 3-, 4-, and 3,5-positions and biphenyl
mannosides bearing one or two methyl esters on the meta position(s) of the outer phenyl
ring showed high affinity for FimH.10 However, a potential drawback of α-
D-mannoside
ligands with aglycones having biphenyl system directly attached to the mannose moiety
is their limited conformational flexibility, which could hamper an optimal fit with the
tyrosine gate.20 In order to increase the conformational flexibility, the inner phenyl ring of
the biphenyl moiety was replaced by a triazolyl-methyl moiety that is attached to the
outer phenyl ring through a six carbon alkyl chain (Figure 1a). Furthermore, we chose to
evaluate both naphthyl and phenyl moieties as terminal aromatic groups to test the
importance of volume at this position.
2. Results and Discussion
In this report, we describe the modification of the biphenyl mannoside A (Figure
1a) following the synthetic strategy outlined in Figure 1b which involves the preparation
of propargyl-functionalized peracetylated mannose as terminal alkyne component (sugar
template) and azido-methyl esters as coupling partners.
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keep or replacemet
by naphthyl
replacemet
by triazole
OH
HO
HO
HO
O
OH
HO
HO
a
O
N
phenyl or
naphthyl
methyl ester
A
O
N
O
HO
N
5
CO2CH3
O
1. Click conditions
2. De-O-acetylation
spacer elongation
b
OAc
O
AcO
AcO
phenyl or
naphthyl
methyl ester
O
AcO
N3
+
5
O
Figure 1. Design of FimH ligands (a) and synthetic strategy (b).
2.1. Synthesis of terminal alkyne component.
As depicted in (Scheme 1), prop-2-ynyl 2,3,4,6-tetra-O-acetyl-α-D-
mannopyranoside (3) was obtained in two steps from
procedure we have used previously.39 Thus,
D-mannose according to the
D
-mannose (1) was converted into the
corresponding peracetate (2) using pyridine and acetic anhydride. Treatment of (2) with
propargyl alcohol under Lewis acid catalysis afforded the α-anomer (3) selectively in
75% yield.
OH
HO
HO
HO
OAc
O
AcO
AcO
AcO
OAc
O
AcO
AcO
AcO
a
O
b
96%
75%
1
3
2
OH
OAc
O
Scheme 1. Synthesis of propargyl mannoside 3. Reagents and conditions: (a) Ac2O,
pyridine, 0 oC-r.t.; (b) propargyl alcohol, BF3.OEt2, CH2Cl2, -10 oC-r.t.
2.2. Synthesis of azido derivatives
The azides (25-31) having six carbon alkyl chains were synthesized via a three-step
sequence that involved forming methyl esters of hydroxyarylcarboxylic acids followed by
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phenolic O-alkylation with 1,6-dibromohexane and subsequent azide substitution of the
remaining bromide. As outlined in Scheme 2, the synthesis of azides began by forming
methyl esters of compounds of the hydroxybenzoic acid family (4-6), hydroxy-2-
naphthoic acid family (10-12), and 5-hydroxyisophthalic acid (16) under conventional
conditions to give: methyl 2-hydroxybenzoate (7),40 methyl 3-hydroxybenzoate (8),41
methyl 4-hydroxybenzoate (9),42 methyl 1-hydroxy-2-naphthoate (13),43 methyl 3-
hydroxy-2-naphthoate (14),44 methyl 6-hydroxy-2-naphthoate (15),45 and dimethyl 5-
hydroxyisophthalate (17)46 in excellent yields.
OH
OH
a
HO2C
H3CO2C
(90-95%)
7: ortho; 8: meta; 9: para
4: ortho; 5: meta; 6: para
R1
R1
CO2CH3
CO2H
a
(90-92%)
R3
R2
R3
R2
13: R1 = OH; R2 = R3 = H
14: R1 = H; R2 = OH; R3 = H
15: R1 = R2 = H; R3 = OH
10: R1 = OH; R2 = R3 = H
11: R1 = H; R2 = OH; R3 = H
12: R1 = R2 = H; R3 = OH
HO2C
CO2H
H3CO2C
CO2CH3
a
90%
OH
OH
16
17
Scheme 2. Synthesis of methyl esters. Reagents and conditions: (a) H2SO4, (cat.), MeOH,
reflux.
The phenolic O-alkylation of methyl benzoates (7-9), methyl naphthoates (13-15)
and the diester (17) was carried out using 1,6-dibromohexane, K2CO3, and a catalytic
6

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amount of KI in refluxing acetone. The alkylated methyl esters: methyl 2-(6-
bromohexyloxy)benzoate (18), methyl 3-(6-bromohexyloxy)benzoate (19), methyl 4-(6-
bromohexyloxy)benzoate (20),42 methyl 1-(6-bromohexyloxy)-2-naphthoate (21), methyl
3-(6-bromohexyloxy)-2-naphthoate (22), methyl 6-(6-bromohexyloxy)-2-naphthoate
(23), and dimethyl 5-(6-bromohexyloxy)isophthalate (24),47 were obtained in good yields
(Scheme 3).
OH
O(CH2)6Br
a
H3CO2C
H3CO2C
(60-65%)
7: ortho; 8: meta; 9: para
18: ortho; 19: meta; 20: para
R1
R1
CO2CH3
CO2CH3
a
(55-60%) R3
R2
R3
R2
21: R1 = O(CH2)6Br; R2 = R3 = H
22: R1 = H; R2 = O(CH2)6Br; R3 = H
23: R1 = R2 = H; R3 = O(CH2)6Br
1
2
3
13:
14:
15:
R = OH; R = R = H
1
2
3
R = H; R = OH; R = H
1
2
3
R = R = H; R = OH
H3CO2C
CO2CH3
H3CO2C
CO2CH3
a
(60%)
OH
17
O(CH2)6Br
24
Scheme 3. O-alkylation of methyl esters. Reagents and conditions: (a) 1,6-
dibromohexane, K2CO3, KI (cat.), acetone, reflux (24 h).
It is noteworthy that 1,6-dibromohexane was used in excess to avoid the formation
1
of unwanted products. The H-NMR spectra confirmed the structures of the alkylated
methyl esters by the presence of two triplets around 4.02 and 3.44 ppm for the -CH2OAr
and –CH2Br groups, respectively. In the 13C-NMR spectra, the structures were also
7

ACCEPTED MANUSCRIPT
confirmed by the presence of two peaks around 68.0 ppm for the -CH2OAr group and
33.8 ppm for the –CH2Br group.
Finally, azidation of the alkylated methyl benzoates (18-20), of the methyl 2-
naphthoates (21-23), and of the diester (24) was carried out using NaN3 in DMF at 100 ˚C
to yield the azides: methyl 2-(6-azidohexyloxy)benzoate (25), methyl 3-(6-
azidohexyloxy)benzoate (26), methyl 4-(6-azidohexyloxy)benzoate (27)47 , methyl 1-(6-
azidohexyloxy)-2-naphthoate (28), methyl 3-(6-azidohexyloxy)-2-naphthoate (29),
methyl
6-(6-azidohexyloxy)-2-naphthoate
(30),
and
dimethyl
5-(6-
azidohexyloxy)isophthalate (31)47 in good yields (Scheme 4).
O(CH2)6N3
O(CH2)6Br
a
H3CO2C
H3CO2C
(70-75%)
25: ortho; 26: meta; 27: para
18: ortho; 19: meta; 20: para
R1
R1
CO2CH3
CO2CH3
a
(67-70%)
R3
R2
R3
R2
21: R1 = O(CH2)6Br; R2 = R3 = H
22: R1 = H; R2 = O(CH2)6Br; R3 = H
23: R1 = R2 = H; R3 = O(CH2)6Br
28:
29:
30:
1
R = O(CH2)6N3; R2 = R3 = H
1
2
3
R = H; R = O(CH2)6N3; R = H
1
2
3
R = R = H; R = O(CH2)6N3
H3CO2C
CO2CH3
H3CO2C
CO2CH3
a
(70%)
O(CH2)6Br
24
O(CH2)6N3
31
Scheme 4. Azidation of alkylated methyl esters. Reagents and conditions: (a) NaN3,
DMF (100 oC), 24 h.
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13
The C-NMR spectra were a good indicator for the formation of azides, as each
contained a new peak around 51.0 ppm for the -CH2N3 carbon and did not contain a peak
at 33.8 ppm that was due to the –CH2Br group.
2.3. Synthesis of acetylated mannosides via click chemistry
With the key intermediates, propargyl mannoside (3) and azido derivatives (25-31)
in hand, we used copper-catalyzed click chemistry to combine them.38,48,49 Thus, the
Huisgen [3+2] cycloadditions between the sugar alkyne and the various synthesized
azides were easily realized under the promotion of sodium ascorbate and copper sulphate
pentahydrate in a mixture of THF and H2O at room temperature, affording the desired
acetylated α-D-mannosides (32-38) in excellent yields (Scheme 5). The structures of
products (32-38) were supported by the appearance of the signals of triazole protons at
7.57, 7.56, 7.53, 7.59, 7.61, 7.58, and 7.66 ppm, respectively, in their 1H-NMR spectra. In
the 13C-NMR spectra, the triazole carbons appeared at 143.4 and 122.9 ppm for
compound (32), 143.6 and 122.8 ppm for compound (33), 143.5 and 122.9 ppm for
compound (34), 143.5 and 122.8 ppm for compound (35), 143.4 and 122.9 ppm for
compound (36), 143.4 and 122.9 ppm for compound (37), and 143.2 and 122.8 ppm for
compound (38), further confirming their structures.
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OAc
O
AcO
AcO
AcO
Aromatic
methyl
ester
O
N3
+
5
O
3
a
(90-92%)
25-31
OAc
O
AcO
N
AcO
AcO
Aromatic
methyl
ester
O
N
N
5
O
32: aromatic methyl ester = 7
33: aromatic methyl ester = 8
34: aromatic methyl ester = 9
35: aromatic methyl ester = 13
36: aromatic methyl ester = 14
37: aromatic methyl ester = 15
38: aromatic methyl ester = 17
Scheme 5. Synthesis of acetylated α-
D
-mannosides. Reagents and conditions: (a)
CuSO4.5H2O, sodium ascorbate, THF/H2O (1:1) ratio, (25 oC), 24 h.
2.4. Removal of O-acetyl protecting groups
Due to the poor solubility of acetylated α-D-mannosides (32-38) in methanol, the
mannosides were dissolved in a 1:1 mixture of THF and methanol and treated with 0.5 M
NaOCH3/methanol solution for 4 h at room temperature. Neutralization by the addition of
ion-exchange resin Amberlite IR-120(H+) until pH = 7 gave the corresponding de-O-
acetylated α-D-mannosides (32A-38A) in excellent yields (Scheme 6). Removal of the
acetates from compounds (32-38) was confirmed by the disappearance of the signals of
1
13
the methyl protons in the H-NMR spectra and those of the methyl carbons in the C-
NMR spectra.
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OAc
O
AcO
AcO
AcO
N
Aromatic
methyl
ester
O
N
N
5
O
32-38
a
(87-90%)
OH
O
HO
N
HO
HO
Aromatic
methyl
ester
O
N
N
5
O
32A: aromatic methyl ester = 7
33A: aromatic methyl ester = 8
34A: aromatic methyl ester = 9
35A: aromatic methyl ester = 13
36A: aromatic methyl ester = 14
37A: aromatic methyl ester = 15
38A: aromatic methyl ester = 17
Scheme 6. De-O-acetylation of monovalent α-D-mannosides. Reagents and conditions:
(a) 0.5 M MeONa in MeOH/THF (1:1 ratio), 25 oC, 4h.
2.5. Biological Activity
The mannoside ligands (32A-38A) were tested as inhibitors of the
hemagglutination22,26 of quinea-pig erythrocytes by type 1 piliated E. coli strain HB101
(pPKI4). The result of the hemagglutination test is expressed as inhibition titer (IT) that
indicates the lowest concentration of the inhibitor at which no agglutination occurs. The
inhibition titer (IT) is then compared to a reference inhibitor such as methyl α-D-
mannoside (MeαMan) giving relative inhibition titer (RIT). The results of the tested
ligands are summarized in Table 1 below.
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Table 1: Inhibition of hemagglutination of quinea-pig erythrocytes
by type1 piliated E. coli strain HB101 (pPKI4)
bRIT
Tested ligand
HAIa(mM)
MeαMan
32A
9.6
1
0.296
0.205
0.169
0.091
0.073
0.047
0.135
32
47
33A
57
34A
105
131
204
71
35A
36A
37A
38A
a
b
. Based on the average value from three independent tests. Based on the reference inhibitor MeαMan
All tested ligands showed better inhibitory potency than the reference inhibitor
MeαMan. The meta (33A) and the para (34A) orientational isomers showed a 47-fold
and 57-fold improvement in activity relative to the standard inhibitor methyl α-D-
mannoside (MeαMan) and were found to be more effective than the ortho isomer. This
result implies that the ortho substitution was less preferred for activity while the para
substitution was preferred to the meta substitution. However, incorporation of a second
methyl ester in the other meta position of ligand (33A) such as ligand (38A) showed a
significant a 71-fold improvement in potency relative to MeαMan. In fact, this constitutes
a 1.5-fold improvement in activity relative to the meta monoester ligand (33A). As
expected, the naphthyl-based ligands (35A-37A) showed better activity than the
analogous phenyl-based mannoside ligands (32A-34A). We presume that the naphthyl
residue contacts a larger proportion of the tyrosine gate. In the series of naphthyl-based
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mannosides, ligand (37A) was found to be the most potent and showed 200-fold
improvement in potency relative to methyl α-D-mannoside.
In order to compare these results to those from previous studies, we have complied a
Table listing results from many studies (Table S1 in supporting information). Most
studies compare new compounds to those for either methyl α-D-mannopyranoside as here
or heptyl α-D-mannopyranoside, found to be 29 times more effective than the former in a
direct comparison.24 The phenyl glycoside is about half as effective as heptyl α-
D
-
mannopyranoside and simple biphenyl glycosides are about 15 times more effective.10
The best compound prepared here was found to be about 200 times better than methyl α-
D
-mannopyranoside or about 7 times better than heptyl α-D-mannopyranoside. Mannosyl
triazoles with N-substituents on the triazole rings being substituted phenyl groups or
substituted benzyl groups have been evaluated before but none were found to be as
effective as the heptyl glycoside.24 Although the implemented chemistry presented in this
work is rather simple and standard, the obtained mannoside ligands are novel and
interesting. Indeed, the outcome of this study is seven mannoside ligands that are
structurally different from those previously reported.
3. Conclusions
In summary, application of simple chemical transformations of aromatic hydroxy
acids (benzoic and naphthaoic) has generated a series of alkyl azide-modified aromatic
methyl esters. Click coupling between known prop-2-ynyl 2,3,4,6-tetra-O-acetyl-α-
D
D
-
-
mannopyranoside and the prepared azides allowed efficient syntheses of unique α-
13

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mannoside ligands having a flexible tail (aglycone) that combines alkyl and aryl moieties.
The inhibitory capacity of the obtained ligands (32A-38A) listed in Table 1 toward FimH
lectin were determined using a hemagglutination assay. All screened ligands show much
better inhibitory activity than the standard inhibitor, methyl α-D-mannopyranoside.
Unlike their phenyl counterparts, the naphthyl-based mannosides (35A-37A) showed
better activity with ligand (37A) being the most active. It is significantly better than
previously studied triazole mannosides and also heptyl α-D-mannopyranoside. Hence, it
is a logical starting point for further development.
4. Experimental section
4.1 Hemagglutination tests
A recombinant type 1 fimbriated E. coli strain, E. coli HB 101 (pPKl4), used was
cultured according to the protocol reported in the literature.22,26 Guinea pig erythrocytes
were isolated and used as described.22,26 Hemagglutination tests were performed in V-
shaped 96-well microtitre plates (Nunc). The compounds were suspended in distilled
deionized water and serially diluted solutions (10 µl) were thoroughly mixed with
bacteria suspension (10 µl) in wells. After 10 min, guinea pig erythrocytes (10 µl) were
added and hemagglutination was read after approximately 10min at room temperature.
4.2. Synthesis
4.2.1 General
Melting points were determined with a SMP3 melting point apparatus and are
1
13
uncorrected. H and C-NMR spectra were recorded at 300 K in 5 mm NMR tubes on
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solutions in CDCl3 on a Bruker Avance 400 MHz spectrometer operating at 400 MHz and
1
13
100 MHz for H-NMR spectra and C-NMR spectra, respectively, with TMS as internal
reference unless otherwise indicated. The carbon and hydrogen atoms were assigned
following analysis of their one dimensional (1H, 13C) and two dimensional (COSY, HSQC,
and HMBC) NMR spectral data. Chemical shifts are given in parts per million (ppm) (+/-
0.01 ppm). Data are presented as follows: chemical shift, multiplicity (s = singlet, bs =
broad singlet, d = doublet, t = triplet, q = quartet, m = multiplet, ABq = AB quartet),
coupling constant (J) in Hertz (Hz). High-resolution mass spectra were recorded on a
Bruker Micro-TOF mass spectrometer using electrospray ionization. The reactions were
monitored by thin layer chromatography (TLC) on Merk silica gel 60 F254 plates.
Compounds were visualized by UV light (λ= 254 nm) and were located by spraying the
plate with a solution of 2% ceric sulfate in 1M H2SO4 followed by heating on a hot plate
until color developed. Compounds were purified on silica gel (70-230 mesh) by column
chromatography using specified eluents. Dichloromethane (DCM) was first dried with
calcium chloride, and refluxed over calcium hydride for one hour followed by distillation.
Pyridine was dried by refluxing over calcium hydride followed by distillation over
activated 4Å molecular sieves.
4.2.2. General Procedure for Alkylation of Methyl Esters
Compounds (18, 19, and 21-23) were synthesized according to the following
procedure. To a stirred solution of methyl ester in acetone (200 mL), 1,6-dibromohexane
(3 equiv.) and K2CO3 (3 equiv.) were added. The resulting reaction mixture was refluxed
15

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for 48 h then cooled to room temperature, filtered and concentrated. Purification was then
achieved by either recrystallization or column chromatography.
4.2.2.1. Methyl 2-(6-bromohexyloxy)benzoate (18)
The general procedure with compound 7 (3.10 g, 20.3 mmol) and 1,6-
dibromohexane (9.3 mL, 60.9 mmol), followed by column chromatography
(EtOAc:Hexanes, 1:7, Rf = 0.5) afforded compound 18 as a pale yellow oil (4.50 g, 60%):
1H NMR δ 7.77- 6.93 (m, 4H, Ar-H), 4.04 (t, J = 6.4 Hz, 2H, OCH2), 3.88 (s, 3H, OCH3),
13
3.42 (t , J = 6.4 Hz, 2H, CH2Br), 1.85-1.25 (m, 8H, OCH2(CH2)4CH2Br); C NMR δ
166.6 (C=O), 158.8, 131.2, 129.2, 121.7, 119.7, 112.8 (Ar-C), 68.7 (OCH2), 53.7
(OCH3), 33.4 (CH2Br), 29.7, 28.5, 27.9, 25.3 (BrCH2(CH2)4CH2O). HRMS (ESI): m/z
calcd for C14H19BrNaO3 [M+Na]+ 337.0415. Found 337.0421.
4.2.2.2. Methyl 3-(6-bromohexyloxy)benzoate (19)
The general procedure with compound 8 (3.00 g, 19.70 mmol) and 1,6-
dibromohexane (9.1 mL, 59.10 mmol), followed by column chromatography
(EtOAc:Hexanes, 1:7, Rf = 0.5) afforded compound 19 as a colorless viscous oil (4.50 g,
1
72%): H NMR δ 7.58-7.02 (m, 4H, Ar-H), 3.93 (t, J = 6.4 Hz, 2H, OCH2), 3.85 (s, 3H,
13
OCH3), 3.36 (t , J = 6.8 Hz, 2H, CH2Br), 1.85-1.44 (m, 8H, OCH2(CH2)4CH2Br); C
NMR δ 166.7 (C=O), 158.9, 131.2, 129.2, 121,7, 119.7, 114.5 (Ar-C), 67.7 (OCH2), 52.0
(OCH3), 33.6 (CH2Br), 32.5, 28.9, 27.8, 25.1 (BrCH2(CH2)4CH2O). HRMS (ESI): m/z
calcd for C14H19BrNaO3 [M+Na]+ 337.0415. Found 337.0423.
16

ACCEPTED MANUSCRIPT
4.2.2.3. Methyl 1-(6-bromohexyloxy)-2-naphthoate (21)
The general procedure with compound 13 (3.00 g, 14.8 mmol) and 1,6-
dibromohexane (6.80 mL, 44.4 mmol), followed by column chromatography
(EtOAc:Hexanes, 1:7, Rf = 0.5), afforded compound 21 as a pale orange viscose oil (4.0g,
74%): 1H NMR δ 8.27-7.53 (m, 6H, naphthalene-H), 4.10 (t, J = 6.5, 2H, OCH2), 3.95 (s,
3H, OCH3), 3.42 (t, J = 6.8, 2H, CH2Br), 1.97-1.54 (m, 8H, OCH2(CH2)4CH2Br); 13C
NMR δ 166.7 (C=O), 157.3, 136.6, 128.7, 128.2, 127.8, 126.7, 126.4, 123.6, 123.4,
119.2 (naphthalene-C), 76.1 (OCH2), 52.1 (OCH3), 33.8 (CH2Br), 33.8, 32.7, 28.0, 25.3
(BrCH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C18H21BrNaO3 [M+Na]+ 387.0572.
Found 387.0564.
4.2.2.4. Methyl 3-(6-bromohexyloxy)-2-naphthoate (22)
The general procedure with compound 14 (3.00 g, 14.8 mmol) and 1,6-
dibromohexane (6.8 mL, 44.4 mmol), followed by column chromatography
1
(EtOAc:Hexanes, 1:7, Rf = 0.4), afforded compound 22 as a yellow oil (3.7g, 55%): H
NMR δ 8.45-7.50 (m, 6H, Ar-H), 4.28 (t, J = 6.4, 2H, OCH2), 4.11 (s, 3H, OCH3), 3.60
(t, J = 6.7, 2H, CH2Br), 2.11-1.72 (m, 8H, OCH2(CH2)4CH2Br); 13C NMR δ 166.9
(C=O), 155.1, 136.1, 132.6, 128.7, 128.3, 127.5, 126.4, 124.3, 122.2, 107.7 (naphthalene-
C), 68.5 (OCH2), 52.2 (OCH3), 33.9 (CH2Br), 32.7, 29.00, 27.9, 25.3
(BrCH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C18H21BrNaO3 [M+Na]+ 387.0572.
Found 387.0569.
17

ACCEPTED MANUSCRIPT
4.2.2.5. Methyl 6-(6-bromohexyloxy)-2-naphthoate (23)
The general procedure with compound 15 (1.96 g , 9.69 mmol ) and 1,6-dibromohexane
(3.0 mL, 19.4 mmol), followed by recrystallization from EtOAc afforded compound 23
as an off white solid (2.0 g, 56%): mp 55 ˚C; 1H NMR δ 8.52-7.13 (m, 6H, Ar-H), 4.09 (t,
J = 6.3, 2H, OCH2), 3.96 (s, 3H, OCH3), 3.44 (t, J = 6.7, 2H, CH2Br), 1.91-1.54 (m, 8H,
OCH2(CH2)4CH2Br); 13C NMR δ 167.5 (C=O), 159.1, 137.3, 130.9, 127.9, 126.8, 126.0,
125.2, 119.9, 106.5 (naphthalene-C), 68.0 (OCH2), 52.1 (OCH3), 33.8 (CH2Br), 32.7,
29.1, 28.0, 25.4 (OCH2(CH2)4CH2Br). HRMS (ESI): m/z calcd for C18H21BrNaO3
[M+Na]+ 87.0572. Found 387.0570.
4.2.3. General Procedure for the Synthesis of Azido-Compounds.
To a stirred solution of alkylated methyl ester in DMF (40 mL) was added NaN3
(2 equiv.) and the resulting reaction mixture was stirred for 24 hrs at 100˚C, cooled down
to room temperature, and filtered. The filtrate was washed with water (75 mL) and the
product was extracted with diethyl ether (3 x 50 mL). The combined organic extracts
were dried over anhydrous Na2SO4, filtered and concentrated. Purification was then
achieved by column chromatography (EtOAc:Hexanes, 1:1).
4.2.3.1. Methyl 2-(6-azidohexyloxy)benzoate (25)
The general procedure with compound 18 (3.50 g, 11.1 mmol) and NaN3 (1.44 g,
22.2 mmol), yielded a yellow oil (2.40 g, 75%): Rf = 0.9 (EtOAc/Hexanes,1:1); 1H NMR
δ 7.84-6.82 (m, 4H, Ar-H), 3.90 (t, J = 6.9, 2H, OCH2 ), 3.72 (s, 3H, OCH3), 3.15 (t, J =
6.4, 2H, CH2N3), 1.70-1.24 (m, 8H, OCH2(CH2)4CH2N3); 13C NMR δ 166.5 (C=O),
158.1, 133.0, 131.1, 119.6, 112.8 (Ar-C), 68.2 (OCH2), 51.4 (CH3), 50.9 (CH2N3), 28.6,
18

ACCEPTED MANUSCRIPT
28.4, 26.0, 25.2 (N3CH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C14H19N3Na1O3
[M+Na]+ 300.1324. Found 300.1328.
4.2.3.2. Methyl 3-(6-azidohexyloxy)benzoate (26)
The general procedure with compound 19 (3.50 g, 11.1 mmol) and NaN3 (1.44 g,
22.2 mmol), yielded a yellow oil (2.00 g, 66%): Rf = 0.9 (EtOAc/Hexanes,1:1). 1H NMR:
δ 7.59-7.03 (m, 4H, Ar-H), 3.94 (t, J = 6.4, 2H, CH2O), 3.86 (s, 3H, OCH3), 3.22 (t, J =
6.6, 2H, CH2N3), 1.79-1.32 (m, 8H, OCH2(CH2)4CH2N3); 13C NMR: δ 166.7 (C=O),
158.9, 131.2, 129.2, 121.7, 119.6, 114.5 (Ar-C), 67.8 (OCH2), 51.9 (CH3), 51.2 (CH2N3),
28.9, 28.6, 26.3, 25.5 (N3CH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C14H19N3NaO3
[M+Na]+ 300.1324. Found 300.1291.
4.2.3.3. Methyl 1-(6-azidohexyloxy)-2-naphthoate (28)
The general procedure with compound 21 (3.50 g, 9.60 mmol) and NaN3 (1.25 g,
19.2 mmol), yielded a brown to redish oil (1.80 g, 60%): Rf = 0.9 (EtOAc/Hexanes,1:1);
1H NMR δ 8.27-7.53 (m, 6H, naphthalene-H), 4.12 (t, J = 6.5, 2H, CH2O), 3.97 (s, 3H,
13
OCH3), 3.29 (t, J = 6.9, 2H, CH2N3), 1.98-1.44-1.98 (m, 8H, OCH2(CH2)4CH2N3); C
NMR: δ 166.8 (C=O), 157.4, 136.7, 128.8, 128.3, 127.9, 126.7, 126.5, 123.6, 123.5,
119.3 (naphthalene-C), 76.3 (OCH2), 52.3 (OCH3), 51.5 (CH2N3), 30.3, 28.9, 26.7, 25.8
(N3CH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C18H21N3NaO3 [M+Na]+ 350.1481.
Found 350.1486.
4.2.3.4. Methyl 3-(6-azidohexyloxy)-2-naphthoate (29)
The general procedure with compound 22 (1.20 g , 3.30 mmol) and NaN3 (0.43 g,
1
6.6 mmol), yielded a pale yellow oil (0.86 g , 67%): Rf = 0.9 (EtOAc/Hexanes,1:1); H
19

ACCEPTED MANUSCRIPT
NMR δ 8.52-7.14 (m, 6H, naphthalene-H), 4.10 (t, J = 6.9, 2H, OCH2), 3.96 (s, 3H,
OCH3), 3.30 (t, J = 6.4, 2H, CH2N3), 1.90-1.48 (m, 8H, OCH2(CH2)4CH2N3); 13C NMR δ
166.9 (C=O), 155.1, 136.1, 132.6, 128.7, 128.3, 127.5, 126.4, 124.3, 122.1, 107.7
(naphthalene-C), 68.5 (OCH2), 52.2 (OCH3), 51.4 (CH2N3), 29.0, 28.8, 26.5, 25.7
(N3CH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C18H21N3NaO3 [M+Na]+ 350.1481.
Found 350.1392.
4.2.3.5. Methyl 6-(6-azidohexyloxy)-2-naphthoate (30)
The general procedure with compound 23 (1.00 g, 2.74 mmol) and NaN3 (0.36 g,
5.5 mmol), yielded an off white solid (0.93 g, 70%): mp 51-53 ˚C; 1H NMR (acetone-d6)
δ 8.52-7.14 (m, 6H, naphthalene-H), 4.10 (t, J = 6.8, 2H, OCH2), 3.96 (s, 3H, OCH3),
13
3.30 (t, J = 6.4, 2H, CH2N3), 1.90-1.46 (m, 8H, OCH2(CH2)4CH2N3); C NMR δ 167.5
(C=O), 159.1, 137.3, 131.0, 130.9, 128.0, 126.9, 126.0, 125.3, 119.9, 106.5 (naphthalene-
C), 68.0 (OCH2), 52.2 (OCH3), 51.5 (CH2N3), 29.1, 28.9, 26.6, 25.8
(N3CH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C18H21N3NaO3 [M+Na]+ 350.1481.
Found 350.1498.
4.2.4. General procedure for the synthesis of acetylated mannosides (32-38)
To a stirred solution of azide and propargyl mannoside (1 equiv.) in THF (35 mL)
was added sodium ascorbate (154 mg) followed by copper (II) sulphate pentahydrate (77
mg, in 35mL of H2O) in one portion, the heterogeneous mixture was stirred vigorously
for 24 hrs. THF was then removed under reduced pressure and CH2Cl2 (50 mL) was
added. The organic layer was separated, dried over MgSO4, filtered and concentrated.
20

ACCEPTED MANUSCRIPT
4.2.4.1. Mannoside (32)
The general procedure with compound 25 (0.60 g, 2.16 mmol) and propargyl
mannoside 3 (0.84 g, 2.16 mmol), followed by purification by column chromatography
1
(EtOAc:Hexanes, 1:1, Rf = 0.2) afforded compound 32 as a pale yellow oil (90%): H
NMR δ 7.73-6.89 (m, 4H, Ar-H), 7.57 (s, 1H, triazole H), 5.27-5.19 ( m, 3H, H-2, H-3,
H-4), 4.91 (s, 1H, H-1), 4.92, 4.78 (ABq, JAB = 12.2 Hz, 2H, H-1'), 4.34 (t, J = 7.2, 2H,
CH2N), 4.26 (dd, J = 12.1, 5 Hz, 1H, H-6b), 4.08-3.97 (m, 4H, H-5, H-6a, Ar-OCH2),
3.83 (s, 3H, OCH3), 2.10-1.36 (m, 20H, NCH2(CH2)4OCH2, COCH3); 13C NMR δ 170.7,
170.0, 169.9, 169.7, 166.7 (5 x C=O), 158.5, 133.4, 131.5, 120.3, 120.1, 113.1 (Ar-C),
143.4 (CH=C), 122.9 (CH=C), 96.8(C-1), 69.4 (C-5), 69.0 (C-2), 68.7 (C-3), 68.4(Ar-
OCH2), 66.0 (C-4), 62.4 (C-1'), 61.0 (C-6), 51.9 (OCH3), 50.2 (NCH2), 30.1, 28.4, 26.0,
25.3 (NCH2(CH2)4CH2O), 20.9, 20.8, 20.7 (4 x COCH3). HRMS (ESI): m/z calcd for
C31H41N3NaO13 [M+Na]+ 686.2537. Found 686.2630.
4.2.4.2. Mannoside (33)
The general procedure with compound 26 (0.66 g, 2.38 mmol) and propargyl
mannoside 3 (0.93 g, 2.38 mmol), followed by purification by column chromatography
(EtOAc:Hexanes, 1:1, Rf = 0.2) afforded mannoside 33 as a colorless viscous oil (90%):
1H NMR δ 7.60-7.04 (m, 4H, Ar-H), 7.56 (s, 1H, triazole H), 5.30-5.22 ( m, 3H, H-2, H-
3, H-4), 4.93 (s, 1H, H-1), 4.82, 4.66 (ABq, JAB = 12 Hz, 2H, H-1'), 4.36 (t, J = 8, 2H,
CH2N), 4.29 (dd, J = 12, 4 Hz, 1H, H-6b), 4.10-3.96 (m, 4H, H-5, H-6a, Ar-OCH2), 3.88
13
(s, 3H, OCH3), 2.13-1.41 (m, 20H, NCH2(CH2)4OCH2, COCH3); C NMR δ 170.8,
170.1, 170.0, 169.8, 167.0 (5 x C=O), 159.0, 131.5, 129.5, 122.0, 120.0, 114.7 (Ar-C)
21

ACCEPTED MANUSCRIPT
143.6 (CH=C), 122.8 (CH=C), 96.9 (C-1), 69.5 (C-5), 69.1(C-2), 68.8 (C-3), 67.9 (Ar-
OCH2), 66.2 (C-4), 62.5 (C-1'), 61.2 (C-6), 52.3 (OCH3), 50.4 (NCH2), 30.3, 29.0, 26.3,
25.6 (NCH2(CH2)4CH2O), 21.0, 20.9, 20.8 (4 x COCH3). HRMS (ESI): m/z calcd for
C31H41N3NaO13 [M+Na]+ 686.2537. Found 686.2485.
4.2.4.3. Mannoside (34)
The general procedure with compound 27 (0.60 g, 2.16 mmol) and propargyl
mannoside 3 (0.84 g, 2.16 mmol), followed by purification by column chromatography
1
(EtOAc:Hexanes, 1:1, Rf = 0.2) afforded compound 34 as a pale yellow syrup (90%): H
NMR δ 7.91-6.81 (m, 4H, Ar-H), 7.53 (s, 1H, triazole H), 5.25-5.18 ( m, 3H, H-2, H-3,
H-4), 4.89 (s, 1H, H-1), 4.88, 4.61 (ABq, JAB = 12.3 Hz, 2H, H-1'), 4.32 (t, J = 7.2, 2H,
CH2N), 4.24 (dd, J = 12.2, 5 Hz, 1H, H-6b), 4.06-3.92 (m, 4H, H-5, H-6a, Ar-OCH2),
3.81 (s, 3H, OCH3), 2.08-1.34 (m, 20H, NCH2(CH2)4OCH2, COCH3); 13C NMR δ 170.6,
170.0, 169.9, 169.6, 166.8 (5 x C=O), 162.7, 131.5, 122.4, 114.0 (Ar-C), 143.5 (CH=C),
122.7 (CH=C), 96.8 (C-1), 69.4 (C-5), 69.0 (C-2), 68.7 (C-3), 67.7 (Ar-OCH2), 66.0 (C-
4), 62.3 (C-1'), 61.0 (C-6), 51.9 (OCH3), 50.2 (NCH2), 30.1, 28.8, 26.2, 25.4
(NCH2(CH2)4CH2O), 20.8, 20.7, 20.6 (4 x COCH3). HRMS (ESI): m/z calcd for
C31H41N3NaO13 [M+Na]+ 686.2537. Found 686.2531.
4.2.4.4. Mannoside (35)
The general procedure with compound 28 (0.41 g, 1.25 mmol) and propargyl
mannoside 3 (0.50 g, 1.25 mmol), followed by column chromatography (EtOAc:Hexanes,
1
1:1, Rf = 0.2) afforded mannoside 35 as a colorless viscous oil (90%): H NMR δ 8.24-
7.52 (m, 6H, naphthalene-H), 7.59 (s, 1H, triazole H), 5.32-5.24 ( m, 3H, H-2, H-3, H-4),
22

ACCEPTED MANUSCRIPT
4.95 (s, 1H, H-1), 4.84, 4.67 (ABq, JAB = 12.3 Hz, 2H, H-1'), 4.39 (t, J = 7.1, 2H, CH2N),
4.30 (dd, J = 12.2, 5 Hz, 1H, H-6b), 4.12-4.09 (m, 4H, H-5, H-6a, Ar-OCH2), 4.08 (s, 3H,
OCH3), 1.69-1.23 (m, 20H, NCH2(CH2)4OCH2, COCH3); 13C NMR δ 170.8, 170.1,
170.0, 169.8 ,166.8 (5 x C=O), 157.4, 136.8, 128.8, 128.4, 127.9, 126.8, 126.6, 123.6,
123.5, 119.3 (naphthalene-C), 143.5 (CH=C), 122.8 (CH=C), 96.9 (C-1), 76.1 (Ar-
OCH2), 69.5 (C-5), 69.1(C-2), 68.8 (C-3), 66.1 (C-4), 62.4 (C-1'), 61.2 (C-6), 52.3
(OCH3), 50.4 (NCH2), 30.3, 30.2, 26.5, 25.6 (NCH2(CH2)4CH2O), 20.9, 20.8, 20.7 (4 x
COCH3). HRMS (ESI): m/z calcd for C35H43N3NaO13 [M+Na]+ 736.2694. Found
736.2673.
4.2.4.5. Mannoside (36)
The general procedure with compound 29 (0.60 g , 1.83 mmol) and propargyl
mannoside 3 (0.72 g, 1.83 mmol), followed by column chromatography (EtOAc:Hexanes,
1:1, Rf = 0.2) afforded compound 36 as a yellow oil (90%): 1H NMR δ 8.29-7.18 (m, 6H,
naphthalene-H), 7.61 (s, 1H, trizole H), 5.32-5.24 ( m, 3H, H-2, H-3, H-4), 4.95 (d, J =
1.3, 1H, H-1), 4.82, 4.63 (ABq, JAB = 12.3 Hz, 2H, H-1'), 4.40 (t, J = 7.1, 2H, CH2N),
4.31 (dd, J = 12.2, 5 Hz, 1H, H-6b), 4.19-4.08 (m, 4H, H-5, H-6a, Ar-OCH2), 3.94 (s, 3H,
OCH3), 2.15-1.41 (m, 20H, NCH2(CH2)4OCH2, COCH3); 13C NMR δ 170.7, 170.0,
169.9, 169.7, 166.7 (5 x C=O), 155.0, 136.1, 132.6, 128.6, 128.4, 127.5, 126.4, 124.3,
122.0, 107.6 (naphthalene-C), 143.4 (CH=C), 122.9 (CH=C), 96.8 (C-1), 69.5 (C-5),
69.0 (C-2), 68.7 (C-3), 68.3 (Ar-OCH2), 66.1 (C-4), 62.4 (C-1'), 61.0 (C-6), 52.2 (OCH3),
50.2 (NCH2), 30.1, 28.8, 26.0, 25.4 (NCH2(CH2)4CH2O), 20.9, 20.8, 20.7 (4 x COCH3).
HRMS (ESI): m/z calcd for C35H43N3NaO13 [M+Na]+ 736.2694. Found 736.2710.
23

ACCEPTED MANUSCRIPT
4.2.4.6. Mannoside (37)
The general procedure with compound 30 (0.50 g , 1.53 mmol) and propargyl
mannoside (0.60 g, 1.53 mmol), followed by purification by column chromatography
1
(EtOAc:Hexanes, 1:1, Rf = 0.2) afforded compound 37 as a yellow oil (90%): H NMR
(acetone d6) δ 8.52-7.72 (m, 6H, naphthalene-H), 7.58 (s, 1H, trizole H), 5.33-5.24 ( m,
3H, H-2, H-3, H-4), 4.95 (d, J = 1.2, 1H, H-1), 4.84, 4.67 (ABq, JAB = 12.3 Hz, 2H, H-
1'), 4.39 (t, J = 7.2, 2H, CH2N), 4.30 (dd, J = 12.2, 5 Hz, 1H, H-6b), 4.13-4.07 (m, 4H, H-
5, H-6a, Ar-OCH2), 3.96 (s, 3H, OCH3), 2.15-1.44 (m, 20H, NCH2(CH2)4OCH2,
13
COCH3); C NMR (acetone d6) δ 170.7, 170.0, 169.9, 169.7, 166.7 (5 x C=O), 155.0,
136.1, 132.6, 128.7, 128.4, 127.5, 126.4, 124.3, 122.0, 107.6 (naphthalene-C), 143.4
(CH=C), 122.9 (CH=C), 96.8 (C-1), 69.5 (C-5), 69.0 (C-2), 68.7 (C-3), 68.3 (Ar-OCH2),
66.1 (C-4), 62.4 (C-1'), 61.0 (C-6), 51.9 (OCH3), 50.2 (NCH2), 30.1, 28.8, 26.0, 25.4
(NCH2(CH2)4CH2O), 20.9, 20.8, 20.7 (4 x COCH3). HRMS (ESI): m/z calcd for
C35H43N3NaO13 [M+Na]+ 736.2694. Found 736.2687.
4.2.4.7. Mannoside (38)
The general procedure with compound 31 (0.60 g , 1.79 mmol) and propargyl
mannoside 3 (0.70 g, 1.79 mmol), followed by purification by column chromatography
(EtOAc:Hexanes, 1:1, Rf = 0.2) afforded compound 38 as a pale yellow oil (90%):1H
NMR δ 8.24, 7.71 (2s, 3H, Ar-H), 7.66 (s, 1H, trizole H), 5.33-5.26 ( m, 3H, H-2, H-3, H-
4), 4.88 (s, 1H, H-1), 4.87, 4.70 (ABq, JAB = 12.3 Hz, 2H, H-1'), 4.41 (t, J = 6.2, 2H,
CH2N), 4.31 (dd, J = 12.4, 5.2 Hz, 1H, H-6b), 4.14-4.03 (m, 4H, H-5, H-6a, Ar-OCH2),
13
3.94 (s, 6H, 2 x OCH3), 2.17-1.45 (m, 20H, NCH2(CH2)4OCH2, COCH3); C NMR δ
24

ACCEPTED MANUSCRIPT
170.5, 169.8, 169.7, 169.5, 165.8 (6 x C=O), 158.9, 131.5, 122.6, 119.5 (Ar-C), 143.2
(CH=C), 122.8 (CH=C), 96.6 (C-1), 69.2 (C-5), 68.9 (C-2), 68.5 (C-3), 68.0 (Ar-OCH2),
65.9 (C-4), 62.2 (C-1'), 60.8 (C-6), 52.2 (2 x OCH3), 50.1 (NCH2), 30.0, 28.6, 26.0, 25.3
(NCH2(CH2)4CH2O), 20.7, 20.6, 20.5 (4 x COCH3). HRMS (ESI): m/z calcd for
C33H43N3NaO15 [M+Na]+ 744.2592. Found 744.2585.
4.2.5. General procedure for de-O-acetylation of mannosides (32-38)
To a stirred solution of a given acetylated mannose in CH3OH (5mL) and THF
(5mL) was added sodium methoxide (0.5 M in CH3OH,1 mL), the reaction mixture was
stirred for 4 h at room temperature and neutralized with Amberlite IR120 (H+), filtered
and concentrated. The resulting residue was then purified by column chromatography
(EtOAc/CH3OH = 2:1).
4.2.5.1. Mannoside (32A)
Mannoside 32A prepared from 32 according to the general procedure as a white
solid (87%):1H NMR δ 7.65-6.84 (m, 5H, Ar-H, triazole H), 5.23, 5.07 (2 x bs, 3H, OH),
4.84-4.23 (m, 6H, H-1, H-1', NCH2, OH), 3.89-3.47 (m, 11 H, H-2, H-3, H-4, H-5, H-6,
OCH2, OCH3), 1.80-1.27 (m, 8H, NCH2(CH2)4CH2O); 13C NMR δ 166.8 (C=O), 158.5,
133.5, 131.5, 120.2, 120.0, 113.2 (Ar-C), 143.7 (CH=C), 123.5 (CH=C), 99.5 (C-1), 72.8
(C-5), 71.3 (C-3), 70.6 (C-2), 68.5 (Ar-OCH2), 66.5 (C-4), 61.0 (C-1'), 60.0 (C-6), 51.9
(OCH3), 50.2 (NCH2), 30.1, 28.8, 26.0, 25.3 (NCH2(CH2)4CH2O). HRMS (ESI): m/z
calcd for C23H33N3NaO9 [M+Na]+ 518.2114. Found 518.1762.
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ACCEPTED MANUSCRIPT
4.2.5.2. Mannoside (33A)
Mannoside 33A was prepared from 33 according to the general procedure as a
1
colorless oil (88%): H NMR δ 7.69-7.01 (m, 5H, Ar-H, triazole H), 5.31, 5.14 (2 x bs,
3H, OH), 4.90 (s, 1H, H-1), 4.81 (bs, 1H, OH), 4.69, 4.54 (ABq, JAB = 11.9 Hz, 2H, H-
1'), 4.29-3.76 (m, 13H, H-2, H-3, H-4, H-5, H-6, OCH2, NCH2, OCH3), 1.87-1.33 (m,
8H, NCH2(CH2)4CH2O); 13C NMR δ 167.0 (C=O), 159.0, 131.4, 129.5, 123.6, 119.9,
114.7 (Ar-C), 143.9 (CH=C), 121.9 (CH=C), 99.6 (C-1), 72.9 (C-5), 71.4 (C-3), 70.6 (C-
2), 67.9 (Ar-OCH2), 66.6 (C-4), 61.1 (C-1'), 60.1 (C-6), 52.2 (OCH3), 50.4 (NCH2), 30.2,
29.0, 26.3, 25.6 (NCH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C23H33N3NaO9
[M+Na]+ 518.2114. Found 518.2116.
4.2.5.3. Mannoside (34A)
Mannoside 34A prepared from 34 according to the general procedure as a white
solid (87%): 1H NMR δ 7.94-6.84 (m, 5H, Ar-H, triazole H), 5.15, 5.03 (2 x bs, 3H, OH),
4.91 (s, 1H, H-1), 4.70-4.53 (m, 3H, H-1', OH), 4.30-3.53 (m, 13H, H-2, H-3, H-4, H-5,
13
H-6, OCH2, NCH2, OCH3), 1.88-1.25 (m, 8H, NCH2(CH2)4CH2O); C NMR δ 166.9
(C=O), 162.9, 131.7, 122.5, 114.2 (Ar-C), 143.9 (CH=C), 123.5 (CH=C), 99.6 (C-1),
72.8 (C-5), 71.0 (C-3), 70.2 (C-2), 67.9 (Ar-OCH2), 66.8 (C-4), 61.2 (C-1'), 60.2 (C-6),
51.9 (OCH3), 50.4 (NCH2), 30.2, 29.0, 26.4, 25.6 (NCH2(CH2)4CH2O). HRMS (ESI):
m/z calcd for C23H33N3NaO9 [M+Na]+ 518.2114. Found 518.1981.
4.2.5.4. Mannoside (35A)
Mannoside 35A prepared from 35 according to the general procedure as a
colorless oil (85%): 1H NMR δ 8.18-7.49 (m, 7H, naphthalene-H, triazole H), 5.31, 5.14
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ACCEPTED MANUSCRIPT
(2 x bs, 3H, OH), 4.93 (s, 1H, H-1), 4.91 (bs, 1H, OH), 4.66, 4.54 (ABq, JAB = 12.2 Hz,
2H, H-1'), 4.28 (t, J = 6.7 Hz, 2H, NCH2), 4.01 (t, J = 6.3 Hz, 2H, OCH2), 3.89-3.64 (m,
9H, H-2, H-3, H-4, H-5, H-6, OCH3), 1.87-1.35 (m, 8H, NCH2(CH2)4CH2O); 13C NMR δ
166.8 (C=O), 157.4, 136.8, 128.8, 128.4, 127.9, 126.8, 126.7, 123.6, 123.5, 119.3
(naphthalene-C), 143.9 (CH=C), 123.5 (CH=C), 99.6 (C-1), 76.2 (Ar-OCH2), 72.9 (C-5),
71.5 (C-3), 70.8 (C-2), 66.7 (C-4), 61.2 (C-1'), 60.1 (C-6), 52.3 (OCH3), 50.4 (NCH2),
30.3, 26.5, 25.6 (NCH2(CH2)4CH2O), HRMS (ESI): m/z calcd for C27H35N3NaO9
[M+Na]+ 568.2271. Found 568.2306.
4.2.5.5. Mannoside (36A)
Mannoside 36A prepared from 36 according to the general procedure as yellow oil
1
(87%): H NMR δ 8.23 (s, 1H, triazole-H), 7.76-7.11 (m, 6H, naphthalene-H), 4.93-4.53
(m, 7H, H-1, H-1', OH) 4.27-3.57 (m, 13H, H-2, H-3, H-4, H-5, H-6, OCH3, OCH2,
NCH2), 1.85-1.32 (m, 8H, NCH2(CH2)4CH2O); 13C NMR δ 166.8 (C=O), 155.0, 136.0,
132.5, 128.6, 128.4, 127.4, 126.5, 124.3, 122.0, 107.7 (naphthalene-C), 143.8 (CH=C),
123.6 (CH=C), 99.5 (C-1), 72.8 (C-5), 71.3 (C-3), 70.7 (C-2), 68.4 (Ar-OCH2), 66.6 (C-
4), 61.0 (C-1'), 60.0 (C-6), 52.2 (OCH3), 50.2 (NCH2), 30.1, 28.8, 26.1, 25.4
(NCH2(CH2)4CH2O), (NCH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C27H35N3NaO9
[M+Na]+ 568.2271. Found 568.2310.
4.2.5.6. Mannoside (37A)
Mannoside 37A prepared from 37 according to the general procedure as a white
1
solid (87%): H NMR: (CD3OD) δ 8.02 (s, 1H, triazole-H), 7.97-7.17 (m, 6H,
naphthalene-H), 4.84 (d, J = 1.2, 1H, H-1), 4.79, 4.62 (ABq, JAB = 12.3 Hz, 2H, H-1'),
27

ACCEPTED MANUSCRIPT
4.43 (t, J = 7.9, 2H, NCH2), 4.11 (t, J = 6.2, 2H, OCH2), 3.94(s, 3H, OCH3), 3.32-3.20
13
(m, 6H, H-2, H-3, H-4, H-5, H-6), 1.62-1.38 (m, 8H, NCH2(CH2)4CH2O); C NMR:
(CD3OD) δ 168.9 (C=O), 160.6, 138.9, 131.9, 131.8, 129.2, 128.0, 126.6, 126.2, 121.0,
107.5 (naphthalene-C), 145.3 (CH=C), 125.3 (CH=C), 100.8 (C-1), 75.0 (C-5), 72.5 (C-
3), 72.0 (C-2), 69.0 (Ar-OCH2), 68.6 (C-4), 63.0 (C-1'), 60.7 (C-6), 52.6 (OCH3), 51.3
(NCH2), 31.2, 30.0, 27.2, 26.6 (NCH2(CH2)4CH2O), HRMS (ESI): m/z calcd for
C27H35N3NaO9 [M+Na]+ 568.2271. Found 568.2268.
4.2.5.7. Mannoside (38A)
Mannoside 38A prepared from 38 according to the general procedure as a white
1
solid (87%): H NMR δ 8.21(s, 1H, Ar-H), 7.73 (s, 1H, triazole H), 7.67 (s, 2H, Ar-H),
5.28 (bs, 3H, OH), 4.94 (s, 1H, H-1), 4.72, 4.59 (ABq, JAB = 11.3 Hz, 2H, H-1'), 4.35-
3.56 (m, 14H, H-2, H-3, H-4, H-5, H-6, OCH3, OCH2, NCH2, OH), 1.92-1.39 (m, 8H,
13
NCH2(CH2)4CH2O); C NMR δ 166.1 (2 x C=O), 159.1, 131.7, 122.8, 119.7 (Ar-C),
143.8 (CH=C), 123.5 (CH=C), 99.3 (C-1), 72.8 (C-5), 71.3 (C-3), 70.7 (C-2), 68.3 (Ar-
OCH2), 66.6 (C-4), 61.1 (C-1'), 60.4 (C-6), 52.4 (2 x OCH3), 50.4 (NCH2), 30.2, 26.9,
26.3, 25.5 (NCH2(CH2)4CH2O). HRMS (ESI): m/z calcd for C25H53N3NaO11 [M+Na]+
576.2169. Found 576.2148.
Acknowledgment
We thank the Deanship of research at Jordan University of Science and
Technology (Jordan) for Financial Support and the Department of Chemistry at
Dalhousie University (Canada) for laboratory space.
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