Novel synthesis of disaccharides containing the 2-amino-2-deoxy-β-D- glucopyranosyl unit and L-Glycero-D-Manno- and 7-deoxy-L-Glycero-D-Galacto- heptopyranoses

Article abstract of DOI:10.1246/cl.2004.696

Stereocontrolled syntheses of immunologically relevant heptopyranose disaccharides were achieved in excellent yields by the trimethylsilyl triflate promoted glycosylation of the donor 1,3,4,6-tetra-O-acetyl-2-N-allyloxycarbonyl- 2-amino-2-deoxy-β-D-glucop

Full text of DOI:10.1246/cl.2004.696

696
Chemistry Letters Vol.33, No.6 (2004)
Novel Synthesis of Disaccharides Containing the 2-Amino-2-deoxy-ꢀ-D-glucopyranosyl
Unit and L-Glycero-D-Manno- and 7-Deoxy-L-Glycero-D-Galacto-heptopyranoses
ꢀ
y
y
yy
´
Patrick Martin, Vincent Lequart, Romeo Cecchelli, Paul Boullanger, Dominique Lafont, and Joseph Banoub
Laboratoire de la Barriere Hemato Encephalique, Universite d’Artois - Institut Pasteur de Lille, Lens, France
`
´
´
´
y
´
Laboratoire de Chimie Organique, Universite Claude Bernard Lyon I, Villeurbanne, France
yyDepartment of Biochemistry, Memorial University, St John’s, Canada
(Received March 4, 2004; CL-040242)
Stereocontrolled syntheses of immunologically relevant
a variety of disaccharides were stereospecificly and regioselec-
tively synthesised. The N-allyloxycarbonyl protective group
was easily removed with Pd(0) complexes, thus affording the
free amino group containing glycoside. We report in this com-
munication the successful extension of this method to the syn-
thesis of the immunogically relevant aminoglucosylheptose dis-
accharides 1 and 10.
heptopyranose disaccharides were achieved in excellent yields
by the trimethylsilyl triflate promoted glycosylation of the donor
1,3,4,6-tetra-O-acetyl-2-N-allyloxycarbonyl-2-amino-2-deoxy-
ꢀ-D-glucopyranose with the adequate acceptors.
The glycosyl acceptor benzyl-2,3,4,6-tetra-O-benzyl-L-
glycero-ꢁ-D-manno-heptopyranoside (5) was synthesized in
70% overall yield starting from 2,3,4,6,7-penta-O-acetyl-L-glyc-
ero-ꢁ-D-manno-heptopyranosyl bromide (2).9 The transforma-
tion of glycosyl bromide 2 into the corresponding glycosyl ac-
ceptor 5 was realized via the intermediates 3 and 4 according
to the Hanessian and Banoub procedure (Scheme 1).10
Lipopolysaccharides of Gram-negative bacteria (LPS) have
a profound effect on the mammalian immune system and have
great importance in various human diseases. The LPS structure
is composed of three distinct regions: the lipid A, the core oligo-
saccharides (composed of an inner core and outer core) and the
O-polysaccharide chain. L-Glycero-D-manno-heptose1,2 (LD-
Hep) is considered as a ubiquitous constituent of the inner
core-region of the LPS.3,4
In the course of structural investigations on the precise mo-
lecular structure of lipopolysaccharides of Gram-negative bacte-
ria Vibrio ordalii and Aeromonas salmonicida5 we have isolated
the disaccharide, 7-O-(2-amino-2-deoxy-ꢀ-D-glucopyranosyl)-
L-glycero-D-manno-heptose (1), by hydrolysis of the core oligo-
saccharides with 2 M hydrochloric acid for 1 h at 100 ꢁC. This
aminoglucosylheptose disaccharide 1 appears to be one of the
antigenic determinants of the rough lipopolysaccharide. The
core oligosaccharides have the following structure:
OR2
R2
R
O
O
2O
2O
AcO
R
O
R1
1O
O
AcO
OR1
ZHN
R1
OAc
O
R1
O
a-e
b, g, h
O
AcO
AcO
R
O
O
R1
O
R1
R1
O
O
OR1
Br
OBn
3. R1=R2=Ac
4. R1=Bn, R2=Si(Ph)2t-Bu
5. R1=Bn, R2=H
2
f
7. R1=Bn, R2=Ac, Z=AOC
1. R1=R2=Z=H
OAc
AcO
AcO
O
OAc
AOC= allyloxycarbonyl
AOCHN
L-
α
-D-Hepp
6
OR2
O
R1
PO4
1
HO CH3
O
R2
R
O
f
2O
CH3
O
O
6
6
4
ZHN
O
O
L-α
-D-Hepp-(1
5)-α
-Kdop-(2
R2
3)-L-α
-D-Hepp-(1
Lipid A)
R1O
b, g, h
O
O
R1
O
OR1
R
1O
4
8
9. R1=C(CH3)2, R2=Ac, Z=AOC
10. R1=R2=Z=H
1
β
-D-GlcpN-(1 7)-L-
α
-D-Hepp
a. AgOTf, tetramethylurea, BnOH, 10 °C; b. MeONa, MeOH; c. ClSi(Ph)2t-Bu,
imidazole; d. BrBn, NaH, DMF; e. 3 % HCl, MeOH; f. TMSOTf, CH2Cl2,-30 °C;
g. Pd(PPh3)4, CH2(COOMe)2; h. 10% Pd/C, H2.
R1= R2
R1= H, R2
lipopolysaccharide core of A. salmonicida
=
α
-D-Glcp, lipopolysaccharide core of V. ordali
4)- -D-GalpNAc-(1 4)-
α
α
-D-Hepp-(1
4)-,
=α-D-Galp-(1
Scheme 1.
Similarly, during the studies of the precipitin reaction anti-
gens, possessing a ꢀ-D-GlcpNAc-(1 ! 4)-ꢁ-D-galacto-pyrano-
syl haptenic structure and their specific antibodies, it was found
that the immunologically relevant disaccharide, ꢀ-D-GlcpNAc-
The disaccharide benzyl-7-O-(3,4,6-tri-O-acetyl-2-N-allyl-
oxycarbonyl-2-amino-2-deoxy-ꢀ-D-glucopyranosyl)-2,3,4,6-
tetra-O-benzyl-L-glycero-ꢁ-D-manno-heptopyranoside was syn-
thetisized by reaction between the glycosyl acceptor 5 and the
donor 67,8 in the presence of TMSOTf in stoichiometric amounts
in dry CH2Cl2 at ꢂ30 ꢁC for 18 h, to afford, after conventional
work up, a chromatographically pure, white solid foam disac-
charide (7) in 89% yield.11
(1 ! 6)-7-deoxy-L-glycero-ꢁ-D-galactoheptopyranose
(10),
was a potent inhibitor.6 Owing to their close resemblance, the
syntheses of both aminoglucosylheptose disaccharides 1 and
10 were investigated simultaneously.
We have published the uses of 1,3,4,6-tetra-O-acetyl-2-N-
allyloxycarbonyl-2-amino-2-deoxy-ꢀ-D-glycopyranose (6) as a
potent 1,2-trans-glycosylating agent using Lewis acid as con-
densation promotor.7,8 Using this N-allyloxycarbonyl approach,
Electrospray using a QqTOF MS/MS hybrid instrument was
performed on disaccharide 7. The conventional ES showed a di-
agnostic protonated molecule [M + H]þ at m=z 1033.4460 and
the sodiated molecule [M + Na]þ at m=z 1055.7670. CID
Copyright Ó 2004 The Chemical Society of Japan

Chemistry Letters Vol.33, No.6 (2004)
697
9 H. Paulsen and A. C. Heitman, Liebigs Ann. Chem., 1988, 1061.
10 S. Hanessian and J. H. Banoub, Carbohydr. Res., 53, C13 (1977);
MS/MS of these last selected two molecular ions afforded series
of expected diagnostic product ions, thus confirming the pro-
posed structure.
‘‘ACS Advances in Chemistry Series,’’ (1976), Vol. 39, p 36.
11 mp 120–121 ꢁC; ½ꢁꢃD
23
þ1:6ꢁ (c 0.1, CHCl3); 1H NMR
The 2-N-allyloxycarbonyl-2-deoxy-ꢀ-D-disaccharide 7 was
then subjected to the Zemplen deacetylation, and the N-allylox-
ycarbonyl group was deprotected to the free amino-group using
Pd(PPh3)4 in the presence of an allyl acceptor as previously re-
ported.7,8 This was followed by a hydrogenolysis in the presence
of 10% Pd/C in methanol, leading to the desired aminoglycosyl-
heptose disaccharide ꢀ-D-GlcpN-(1-7)-L-glycero-D-manno-hep-
topyranose 1, in 82% overall yield.12
It may be noted that another approach for the synthesis of
the aminoglucosylheptose disaccharide hydrochloride 1 was
achieved using 3,4,6-tri-O-acetyl-2-azido-2-deoxy-ꢁ-D-gluco-
pyranosyl bromide (3.7 equiv.) and benzyl-2,3,5,6-tetra-O-ben-
zyl-L-glycero-D-manno-heptofuranoside (1 equiv.) in the pres-
ence of silver silicate at ꢂ50 ꢁC and led to an anomeric
mixture of the expected disaccharides.13
The synthesis of disaccharide 6-O-(3,4,6-tri-O-acetyl-2-
N-allyloxycarbonyl-2-amino-2-deoxy-ꢀ-D-glucopyranosyl)-7-
deoxy-1,2:3,4-di-O-isopropylidene-L-glycero-ꢁ-D-galacto-hep-
topyranose (9) was performed by reacting stoichiometric
amounts of the glycosyl donor 6 with 1,2:3,4-di-O-isopropyli-
dene-7-deoxy-L-glycero-ꢁ-D-galacto-heptopyranose (8)14 as
the glycosyl acceptor and TMSOTf in dry CH2Cl2 at ꢂ30 ꢁC
for 18 h to afford, after conventional work up, a chromatograph-
ically pure white solid foam in 79% yield which was crystallized
from ether/EtOAc (72% yield).15
Finally, the 9 was recovered by the deprotection pathway
used in case of disaccharide 7, leading to the expected 6-O-
(-2-N-acetamido-2-deoxy-ꢀ-D-glucopyranosyl)-7-deoxy-L-glyc-
ero-D-galacto-heptopyranose disaccharide (10) in 80% overall
yield.16
(300 MHz, CDCl3): ꢂ 5.89 (m, 1H, CH=CH2), 5.33–5.15 (m,
3H, CH=CH2, H-30), 5.07 (t, 1H, J3 ;4 ¼ 9:5 Hz, H-40), 4.92
(m, 1H NH0), 4.81(m, 1H, H-20); 4.72–4.68 (m, 2H, 2CH-Ph),
4.62–4.48 (m, 4H, CH2-CH=CH2, H-10, H-1, ꢁ-Hep), 4.60 (d,
1H, J ¼ 12:0 Hz, CH-Ph), 4.56 (d, 1H, J ¼ 12:0 Hz, CH-Ph),
4.53 (d, 1H, J ¼ 11:8 Hz, CH-Ph), 4.50 (dd, 1H, H-4), 4.44 (d,
0
0
0
0
1H, J ¼ 11:9 Hz, CH-Ph), 4.21 (m, 2H, J6 a,6 b ¼ 12:3 Hz,
J5;6 ¼ 4:7 Hz, J5;6 ¼ 4:2 Hz, H-6, H-60 non reducing end unit),
0
4.25 (dd, 1H, J1;2 ¼ 4:0 Hz, J2;3 ¼ 4:1 Hz, H-2), 4.27 (dd, 1H,
J3;4 ¼ 2:7 Hz, H-3), 4.31 (dd, 1H, J4;5 ¼ 7:1 Hz, H-5), 3.70 (m,
1H, H-50), 2.09, 2.04, 2.03 (3s, 9H, 3CO-CH3); ESI-QqTOF-
MS-MS: Calcd [M + H]þ m=z 1033.4460, Found [M + H]þ
m=z 1033.6680; Anal. Calcd for C58H66O16N (1033.15): C,
67.42, H, 6.43, N, 1.35. Found: C, 67.72, H, 6.59, N, 1.20%.
12 ½ꢁꢃD þ7:0ꢁ (c 1.0, H2O); 1H NMR (300 MHz, D2O): ꢂ 4.73 (d,
23
1H, H-10), 4.09 (d, 1H, H-1). 3.92 (dd, 1H, J1;2 ¼ 1:8 Hz, J2;3
¼
4:6 Hz, H-2), 3.19 (dd, 1H, H-5), 4.13 (m, 1H, J5;6 ¼ 1:8 Hz,
J6;7 ¼ 6:4 Hz, H-6), 3.69 (dd, 1H, H-3), 3.64–3.52 (m, 3H,
J1;2 ¼ 1:2 Hz, J2;3 ¼ 9:4 Hz, J7a,7b ¼ 11:7 Hz, H-20, H-7a, H-
7b), 3.52 (dd, 1H, J3 ;4 ¼ 9:0 Hz, H-30), 3.48 (d, 2H, H-60),
3.28 (dd, 1H, H-40), 3.17 (dd, 1H, H-50). 13C NMR (125 MHz,
CDCl3): ꢂ 102.4 (C-10), 94.9 (C-1ꢁ), 94.7 (C-1ꢀ), 77.3 (C-5),
76.0 (C-50), 73.0 (C-30), 72.5 (C-3ꢁ), 71.9 (C-3ꢀ), 71.6 (C-
2ꢀ), 71.5 (C-2ꢁ), 68.1 (C-6), 67.1 (C-4ꢁ), 65.6 (C-40), 66.5
(C-4ꢀ), 63.8 (C-7ꢁ), 63.4 (C-7ꢀ), 61.3 (C-60), 55.3 (C-20).
ESI-QqTOF-MS-MS: Calcd [M + H]þ m=z 372.1427, Found
[M + H]þ m=z 372.1627; Anal. Calcd for C58H66O16N
(371.30): C, 42.05, H, 6.78, N, 3.77. Found: C, 42.51, H, 6.61,
N, 3.92%.
0
0
13 H. Paulsen, A. Wulf, and A. C. Heitman, Liebigs Ann. Chem.,
1988, 1073.
14 R. U. Lemieux, P. H. Boullanger, D. R. Bundle, D. A. Baker, A.
Nagpurkar, and A. Venot, Nouv. J. Chim., 2, 321 (1978).
15 mp 165–166 ꢁC; ½ꢁꢃD
23
þ4:1ꢁ (c 1.0, CHCl3); 1H NMR
To sum up, this work provided two stereocontrolled synthe-
ses of immunogically relevant disaccharides which were achiev-
ed in excellent yields using the N-allyloxycarbonyl approach.
The preparation of antigenic branched glycoconjugates
of the poly-N-acetyllactosamine series [ꢀ-D-Galp-(1 ! 4)-
GlcpNAc-(1-]n, using the N-allyloxycarbonyl derivatives of lac-
tosamine is under studies in our laboratories and will be reported
in due course.
(300 MHz, CDCl3): ꢂ 5.99 (m, 1H, CH=CH2), 5.49 (d, 1H,
J1;2 ¼ 5:0 Hz, H-1), 5.28, 5.15 (2m, 2H, CH=CH2), 5.25 (dd,
1H, J2 ;3 ¼ 10:1 Hz, J3 ;4 ¼ 9:5 Hz, H-30, ꢀ-GlcNAOC), 5.06
0
0
0
0
(d, 1H, J1 ;2 ¼ 8:5 Hz, H-10), 4.96 (dd, 1H, J4 ;5 ¼ 10:0 Hz, H-
40), 4.60 (dd, 1H, J2;3 ¼ 2:4 Hz, J3;4 ¼ 8:0 Hz, H-3, ꢁ-Hep),
4.59, 4.43 (2m, 2H, CH2–CH=CH2), 4.33 (dd, 1H, H-2), 4.29
0
0
0
0
0
0
(dd, 1H, J4;5 ¼ 1:5 Hz, H-4), 4.28 (dd, 1H, J5 ,6 a ¼ 5:1 Hz,
J6 a,6 b ¼ 12:2 Hz, H-60a), 4.10 (m, 2H, J5 ,6 b ¼ 2:5, J5 ,6a
¼
0
0
0
0
0
0
2:5 Hz, H-60b), 3.93 (m, 2H, J5;6 ¼ 8:0 Hz, J6,CH3 ¼ 6:6 Hz,
H-6), 3.80 (m, 1H, H-50), 3.70 (m, 1H, H-5), 3.62 (m, 1H,
J2 ,NH ¼ 9:2 Hz, H-20), 2.02, 1.99, 1.93 (3s, 9H, CO-CH3),
Joseph Banoub acknowledges the Natural Sciences and
Engineering Research Council of Canada for a Discovery grant.
0
1.46, 1.40, 1.31, 1.30 (4s, 12H, CH3iso), 1.27 (d, 3H, H-7);
13C NMR (125 MHz, CDCl3): ꢂ 170.7, 170.4, 170.1 (CO–
CH3), 156.2 (CO, allyloxycarbonyl), 134.7 (CH=CH2), 116.8
(CH=CH2), 109.6 (Ciso), 102.4 (C-10, ꢀ-GlcNAOC), 97.0 (C-1,
ꢁ-Hep), 76.2 (C-6), 74.4 (C-5), 72.2 (C-50), 72.0 (C-30) 71.7
(C-2), 71.6 (C-3), 71.2 (C-4), 70.0 (C-40), 65.5 (CH2–CH=CH2),
63.0 (C-60), 51.2 (C-20), 26.4, 26.3, 25.3, 24.5 (CH3iso), 18.1
(C-7, Hep), 21.2, 21.0, 20.9 (3s, 9H, CO-CH3).
References and Notes
Y. A. Knirel, J. H. Helbig, and U. Zahringer, Carbohydr. Res.,
283, 129 (1996).
1
2
3
M. Bruneteau and S. Minka, Biochimie, 85, 145 (2003).
C. Erridge, E. Bennett-Guerrero, and I. R. Poxton, Microbes
Infect., 4, 837 (2002).
23
1
16 ½ꢁꢃD þ10:7ꢁ (c 1.0, H2O); H NMR (300 MHz, D2O): ꢂ 5.12
4
5
Y. A. Knirel, E. Vinogradov, N. Jimenez, S. Merino, and J. M.
Tomas, Carbohydr. Res., 339, 787 (2004).
J. H. Banoub and H. J. Hodder, Can. J. Biochem. Cell Biol., 63,
1199 (1985); J. H. Banoub, F. Michon, and R. Roy, Carbohydr.
Res., 128, 203 (1984).
(d, 1H, J1;2 ¼ 4:0 Hz, H-1ꢁ), 5.09 (d, 1H, J1;2 ¼ 9:0 Hz,
H-1ꢀ), 4.69 (d, 1H, J1 ;2 ¼ 8:0 Hz, H-10), 4.68 (m, 1H, H-6a0),
4.18 (m, 1H, H-6b0), 3.98 (dd, 1H, J2;3 ¼ 5:1 Hz, H-2), 3.76
(m, 1H, H-4), 3.70 (dd, 1H, J2;3 ¼ 3:9 Hz, J3;4 ¼ 10:1 Hz,
H-3), 3.61 (m, 1H, H20), 3.54 (m, 1H, H-5), 3.50 (dd, 1H,
0
0
6
7
8
J. H. Banoub, D. H. Shaw, N. A. Nakhla, and H. J. Hodder, Eur.
J. Biochem., 179, 651 (1989).
P. Boullanger, J. H. Banoub, and G. Descotes, Can. J. Chem., 65,
1343 (1987).
J. H. Banoub, P. Boullanger, and D. Lafont, Chem. Rev., 92,
11676 (1992).
J3 ;4 ¼ 9:0 Hz, H-30), 3.28 (dd, 1H, H-40), 3.17 (dd, 1H, H-50),
1.30 (d, 3H, H-7);. ESI-QqTOF-MS-MS: Calcd [M + H]þ m=z
356.1481, Found [M + H]þ m=z 356.1691; Anal. Calcd for
0
0
C13H25O10N (355.31): C, 42.97, H, 6.94, N, 3.86. Found: C,
42.61, H, 6.82, N, 3.80%.
Published on the web (Advance View) May 17, 2004; DOI 10.1246/cl.2004.696