Convenient syntheses of symmetrical and unsymmetrical glycosyl carbodiimides and N,N-bis(glycosyl)cyanamides.

Article abstract of DOI:10.1016/S0008-6215(02)00108-8

Reaction of glycosyl trimethylphosphinimides with carbon disulfide under mild conditions (room temperature, short reaction time) leads to symmetrical glycosyl carbodiimides. Addition of bis(trimethylsilyl)carbodiimide to peracetylated aldoses under the in

Full text of DOI:10.1016/S0008-6215(02)00108-8

Carbohydrate Research 337 (2002) 1171–1178
www.elsevier.com/locate/carres
Convenient syntheses of symmetrical and unsymmetrical glycosyl
carbodiimides and N,N-bis(glycosyl)cyanamides
a
b
a,
2
La´szlo´ Kova´cs, Erzse´bet Osz, Zolta´n Gyo¨rgydea´k *
aDepartment of Organic Chemistry, Uni6ersity of Debrecen, H-4010 Debrecen, PO Box 20, Hungary
bDepartment of Medicinal Chemistry, Uni6ersity of Pe´cs, H-7624 Pe´cs, Szigeti u´t 12, Hungary
Received 4 February 2002; accepted 11 April 2002
Abstract
Reaction of glycosyl trimethylphosphinimides with carbon disulfide under mild conditions (room temperature, short reaction
time) leads to symmetrical glycosyl carbodiimides. Addition of bis(trimethylsilyl)carbodiimide to peracetylated aldoses under the
influence of SnCl4 afforded N,N-bis(glycosyl)cyanamides for the first time. Readily accessible unsymmetrical N,N%-bis(glyco-
syl)thioureas can be desulfurated and transformed into the corresponding carbodiimides using HgO in CHCl3/water at room
temperature. © 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Glycosyl azides; Glycosyl carbodiimides; Glycosyl cyanamides; Staudinger reaction
1. Introduction
syl thioureas9 by elimination of hydrogen sulfide; (ii)
from glycosyl phosphinimides which could be easily
prepared from the glycosyl azides by Staudinger reac-
tion.10,11 Thiourea-linked pseudooligosaccharides both
symmetrical and unsymmetrical, have been synthesized
by the reaction of sugar isothiocyanates and amino
sugars9 (or glycosyl iminophosphorane).12,13
Sugar carbodiimides are key intermediates in synthe-
ses of various glycoconjugates (trehazolin-type glycosi-
dase inhibitors,1,2 glucocinnamoyl spermidine anti-
biotics,3,4 etc.), which play an important role in biolog-
ical systems.5 These examples of synthetic compounds
with two monosaccharide moieties bound by
a
(thio)urea bridge are limited to symmetrical and unsym-
metrical N,N-bis(glycosyl) derivatives.6 Glycosyl car-
bodiimides are precursors of urea-, thiourea-, and
guanidine-type sugar derivatives, that can be easily
synthesized from the corresponding glycosyl carbodi-
imides by nucleophilic addition of water or hydrogen
sulfide, respectively.7 Another possible application of
carbodiimides is the synthesis of carbohydrate deriva-
tives that could be utilised as core structures for the
construction of dendrimers.8 The use of sugar cores
should lead to potentially biodegradable, non-toxic and
chiral dendrimers. Two general methods are known for
the synthesis of glycosyl carbodiimides: (i) from glyco-
2. Results and discussion
Reaction of peracetylated glycopyranosyl azides14 (b-
D
-gluco 1, a-
2-amino-2-deoxy-b-
a- -arabino 8, b- -arabino 9) (Scheme 1) with 1 equiva-
D
-gluco 2, b-
D
-galacto 3, a-
D
-galacto 4,
D
-gluco 5, b-
D
-manno 6, b-
D
-xylo 7,
D
D
lent of trimethylphosphine in dry dichloromethane at
room temperature led to the corresponding glycosyl
trimethylphosphinimides.15 The in situ reaction of these
compounds with carbon disulfide under mild conditions
led to the symmetrical glycosyl carbodiimides 10–14
(Scheme 2). In the case of the 1,2-trans azides 1, 3, 5, 7,
8, the expected products were obtained in good yields
as stable crystalline solids. The hexopyranosyl carbodi-
imides of
D
-gluco and
D
-galacto configuration 10 and
* Corresponding author. Tel.: +36-52-512900/2453; fax:
+36-52-453836
E-mail address: gyorgydeak@tigris.klte.hu (Z. Gyo¨rgy-
dea´k).
11 were obtained in about 10 min, while formation of
the pentopyranosyl carbodiimides 13 and 14 took about
12 h. From the 1,2-cis azides 2, 4, 6, 9, complex
0008-6215/02/$ - see front matter © 2002 Elsevier Science Ltd. All rights reserved.
PII: S0008-6215(02)00108-8

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L. Ko6a´cs et al. / Carbohydrate Research 337 (2002) 1171–1178
Scheme 1.
pyranoside22 (32) was reacted with methylisothio-
-glucopyranosyl
reaction mixtures were formed, and the expected prod-
ucts could not be isolated but were identified by NMR
spectroscopy. According to Pinte´r and co-workers, the
separation of these mixtures by chromatography is not
possible because the carbodiimides react with traces of
water to give the corresponding glycosyl ureas.16
Peracetylated glycoses can react with trimethylsily-
lated nucleophiles17–19 (azide, cyanide, etc.) in the pres-
ence of a Lewis acid catalyst (SnCl4, BF3·Et2O, etc.)
and the expected, nucleophile containing derivatives are
formed. In order to obtain the symmetric N,N%-bis(gly-
cyanate and 2,3,4,6-tetra-O-acetyl-b-
D
isothiocyanate9 (33) in dry ethylacetate to give the
corresponding N-methyl-N%-glycosyl thiourea 34 and
N,N%-bis(glycosyl) thiourea derivative (35), respectively
(Scheme 6). These compounds can be desulfurated in
excellent yields using HgO in CHCl3–water at room
temperature. The synthesized products 36 and 37 are
crystalline solids.
The structure elucidation of the newly prepared com-
pounds was based mainly on IR and NMR measure-
ments. We have found strong absorptions around 2150
and 2230 cm−1 in the infrared spectra corresponding to
the carbodiimide and cyanamide groups. The presence
cosyl)carbodiimides, peracetylated glycopyranoses (b-
gluco 15, b- -galacto 16, b- -xylo 17, b- -ribo 18,
a- -arabino 19 and a- -lyxo 20, Scheme 3) were treated
D-
D
D
D
D
D
1
of one series of sugar signals in the H as well as 13C
with 1.2 equivalents of freshly prepared bis(trimethylsi-
lyl)carbodiimide.20 Unexpectedly, the reaction of the
aldose derivatives 15–20 furnished complex reaction
mixtures from which the N,N-bis(glycopyranosyl)
cyanamides 21, 23, 25, 27, 30, 31) and N,N-bis(glycopy-
ranosyl) cyanoguanidines 22, 24, 26, 28 could be iso-
lated by column chromatography in convenient yields
(Scheme 4). As Lewis acids tin tetrachloride,
trimethylsilyl triflate and BF3·Et2O were tried. How-
ever, in the case of BF3·Et2O the starting material was
recovered unchanged even after 7 days of continuous
stirring at room temperature. The pentopyranosyl
cyanamide derivatives 25, 27, 30, 31 were obtained
more rapidly than the hexopyranosyl compounds 21
and 23. Starting from 19, we isolated the monosubsti-
tuted cyanamide derivative 29, too (Scheme 5). Further
experiments showed that the pure symmetrical glycosyl
carbodiimides were transformed into the corresponding
cyanamides under the influence of the Lewis acid. Sim-
ilar carbodiimide–cyanamide isomerization have been
observed recently in the case of an aromatic carbodi-
imide in the presence of 2.5 mol % of Pd2(dba)3·CHCl3
and 10 mol % of 1,2-bis(diphenylphosphino)ethane.21
In order to obtain the unsymmetrical carbodiimides,
NMR spectra of these compounds indicates symmetri-
cal bis(glycosyl) structures. The proton assignments
were based on 1H–1H COSY experiments. The 13C
NMR spectra revealed signals characteristic for the
carbodiimide (137–140 ppm) and for the cyanamide
(108–111 ppm) type carbons. 15N NMR spectra of
compounds 13 and 25 indicated the presence of one
(77.2 ppm) versus two nitrogen resonances (45.8 and
196.3 ppm) characteristic for the carbodiimides and
methyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-b-
D
-gluco-
Scheme 2.

L. Ko6a´cs et al. / Carbohydrate Research 337 (2002) 1171–1178
1173
Scheme 3.
Scheme 4.
cyanamides, respectively.23 The conformations of the
knowledge, glycosyl cyanamides are not known in the
literature. We have found that pure symmetrical glyco-
syl carbodiimides were transformed into the corre-
sponding cyanamides under the influence of Lewis acid.
sugar moieties (4C1 for 10–13, 21–28, 31, 34–37 and
1
1C4 for 14, 29, 30) are evident from the vicinal H–1H
1
coupling constants determined from the H NMR spec-
tra (see Section 3). In the case of pentopyranose deriva-
tives the conformer ratio (Table 1) was calculated by
using J4a,5a 11.6 Hz and J4e,5e 1.5 Hz as limiting values
4
1
for the C1 and C4 conformers, respectively taken from
the literature.24 The configurations of the anomeric
3
carbons could be deduced by relying on the JH-1,H-2
values (see Section 3).
In summary, symmetrical and unsymmetrical glyco-
syl carbodiimides, N,N-bis(glycosyl)cyanamides could
be obtained under mild conditions. To the best of our
Scheme 5.

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L. Ko6a´cs et al. / Carbohydrate Research 337 (2002) 1171–1178
Perkin–Elmer 16 PC FT-IR spectrometer. NMR spec-
tra were recorded with Bruker WP 360 SY (360/90
1
MHz for H/13C) and Varian UNITYINOVA 400 WB
(400/100/40 MHz for 1H/13C/15N) spectrometers.
Chemical shifts are referenced to Me4Si (1H), to the
residual solvent signal (13C: 77.00 ppm for CDCl3) or to
NH4Cl (50 mg/700 mL H2O/D2O=9:1) as an external
standard (15N). Measurements were run at 298 K probe
1
temperature. The H and 13C assignments were based
1
on H–1H COSY, gradient enhanced 13C–1H HSQC,
15N–1H HSQC, 13C–1H HMBC and 15N–1H HMBC
experiments measured using standard Varian software.
The designation of peak multiplicities follows the gen-
eral use (s: singlet, d: doublet, t: triplet, Ct: pseudo
triplet, q: quartet, m: multiplet). MALDI-TOF mea-
surements were performed with a Bruker BIFLEX III
mass spectrometer. TLC was performed on DC-
Alurolle, Kieselgel 60 F25 (E. Merck); the plates were
visualized by gentle heating. For column chromatogra-
phy, Kieselgel 60 (E. Merck) was used. Organic solu-
tions were concentrated under diminished pressure at
40–50 °C (water bath). Glycosyl azides (1–9), peracety-
lated aldoses (15–20) were prepared as described in the
literature.18,25,26 Me3P solution (1 M in toluene),
methylisothiocyanate and bis(trimethylsilyl)carbodi-
imide are commercial products of Fluka AG, Buchs,
Switzerland.
General Procedure A for the preparation of symmetric
glycopyranosyl carbodiimides (10–14).—To a solution
of glycosyl azide (1–9) (0.20 g, 0.54 mmol) in dry
CH2Cl2 (2 mL) 1 equiv of trimethylphosphine was
added. The mixture was stirred at room temperature
until the N2 evolution ceased. Then 1.6 equiv of CS2
was added and the resulting mixture was stirred at
room temperature temperature for 12 h (pentopyran-
osyl derivatives) and 1 h (hexopyranosyl derivatives).
Finally, the solution was evaporated and the crude
product was purified by crystallisation.
Scheme 6.
Table 1
Conformational equilibria of
D-pentopyranosyl carbodi-
imides, cyanamides and cyanoguanidinesa in CDCl3
Compound
4C1
1C4
13
14
25
26
27
29
30
31
84
5
82
84
89
7
16
95
18
16
11
93
89
11
Bis(2,3,4,6-tetra-O-acetyl-i-D-glucopyranosyl)carbo-
diimide (10). Prepared from 1 (0.20 g, 0.53 mmol)
according to General Procedure A; Yield: 0.15 g (80%),
colourless crystalline product; mp 177–179 °C
(CH2Cl2–Et2O), lit.11 mp 178 °C; [h]D −42.5° (c 1.0,
CHCl3); lit.11 [h]D −43.0° (c 1.0, CHCl3); w (KBr):
11
89
a Calculated on the basis of J4,5 couplings using J4a,5a 11.6
Hz and J4e,5e 1.5 Hz as limiting values for the 4C1 and 1C4
conformers, respectively as taken from Ref. 24.
2154 (NꢀCꢀN) and 1746 (OAc) cm−1
.
1H NMR
(CDCl3): l 5.12 (Ct, 1H, J3,4 9.5 Hz, H-3), 5.05 (Ct,
1H, J4,5 10.0 Hz, H-4), 4.90 (Ct, 1H, J2,3 8.9 Hz, H-2),
4.68 (d, 1H, J1,2 9.0 Hz, H-1), 4.22 (dd, 1H, J5,6a 4.8 Hz,
J6a,6b 12.1 Hz, H-6a), 4.10 (m, 1H, H-6b), 3.71 (ddd,
1H, J5,6b 2.1 Hz, H-5), 2.05, 1.99, 1.96, 1.93 (s, 12H,
acetyl CH3); 13C NMR (CDCl3): l 170.5, 170.0, 169.2,
169.0 (acetyl CO), 137.9 (NꢀCꢀN), 84.0 (C-1), 73.8,
72.8, 72.4, 67.9 (C-2, C-3, C-4, C-5), 61.6 (C-6), 20.4
(acetyl CH3).
3. Experimental
Distilled dichloromethane was dried by storage over
,
4 A molecular sieves. Melting points were measured on
a Kofler hot-stage and are uncorrected. Optical rota-
tions were recorded in chloroform solution on a
Perkin–Elmer 241 polarimeter in a 1 dm cell at room
temperature (2292 °C). IR spectra were taken with a

L. Ko6a´cs et al. / Carbohydrate Research 337 (2002) 1171–1178
1175
Bis(2,3,4,6-tetra-O-acetyl-i-D-galactopyranosyl)car-
General Procedure B for the preparation of N,N%-
bis(glycopyranosyl)cyanamides (21, 23, 25, 27, 30,
31).—To a solution of peracetylated aldoses (15–20) (2
mmol) in dry CH2Cl2 (10 mL) 0.24 mL (0.2 mmol) of
SnCl4 and 0.54 mL (2.4 mmol) of bis(trimethylsi-
lyl)carbodiimide were added and stirred at room tem-
perature for 12 h (pentopyranosyl derivatives) and 48 h
(hexopyranosyl derivatives). Then the reaction mixture
was diluted with 18 mL of CH2Cl2, washed with cold
saturated NaHCO3 solution and water. After drying of
the CH2Cl2 layer and evaporation of the solvent the
crude product was separated by column chromatogra-
phy using 1:1 EtOAc–hexane as eluent. The fractions
were monitored by TLC (2:1 EtOAc–hexane).
bodiimide (11). Prepared from 3 (0.20 g, 0.53 mmol)
according to General Procedure A; Yield: 0.18 g (95%),
mp 89–91 °C (CH2Cl2–Et2O), lit.11 syrup; [h]D −9.4°
(c 1.0, CHCl3); w (KBr): 2156 (NꢀCꢀN) and 1750 (OAc)
1
cm−1. H NMR (CDCl3): l 5.39 (dd, 1H, J4,5 1.1 Hz,
H-4), 5.15 (dd, 1H, J2,3 9.9 Hz, H-2), 5.00 (dd, 1H, J3,4
2.6 Hz, H-3), 4.74 (d, 1H, J1,2 8.4 Hz, H-1), 4.25–3.90
(m, 3H, H-5, H-6a, H-6b), 2.18, 2.09, 2.06, 1.99 (s, 12H,
acetyl CH3); 13C NMR (CDCl3): l 169.9, 169.8, 169.0,
168.9 (acetyl CO), 137.3 (NꢀCꢀN), 84.4 (C-1), 72.5,
70.7, 69.7, 66.8 (C-2, C-3, C-4, C-5), 60.9 (C-6), 20.5
(acetyl CH3).
Bis(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-i-D-glu-
copyranosyl)carbodiimide (12). (a) Prepared from 5 (0.20
g, 0.53 mmol) according to General Procedure A;
Yield: 0.14 g (71%), colourless crystalline product; mp
212–214 °C (CH2Cl2–Et2O), lit.10 mp 205–210 °C; [h]D
−27.2° (c 1.0, CHCl3); lit.10 [h]D −27.0° (c 1.0,
CHCl3).
N,N-Bis(2,3,4,6-tetra-O-acetyl-i-
cyanamide (21) and N1,N3-bis(2,3,4,6-tetra-O-acetyl-i-
-glucopyranosyl)-N2-cyanoguanidine (22). Prepared
D-glucopyranosyl)-
D
from 15 (0.78 g, 2.00 mmol) according to General
Procedure B; The first fraction (Rf 0.56) gave 0.12 g
(20%) of cyanamide 21 (with 90% conversion) as
colourless crystalline product. Mp 187–190 °C, [h]D
−47.4° (c 1.0, CHCl3); w (KBr): 2230 (N-CꢀN) and
(b) Prepared from 5 (0.38 g, 1.00 mmol) with tri-
phenylphosphine according to General Procedure A;
Yield: 0.20 g (54%), colourless crystalline product; mp
205–206 °C (EtOAc–Et2O). This compound was iden-
1
1752 (OAc) cm−1. H NMR (CDCl3): l 5.30 (dd, 1H,
J3,4 9.5 Hz, H-3), 5.11 (dd, 1H, J4,5 10.0 Hz, H-4), 5.09
(dd, 1H, J2,3 8.9 Hz, H-2), 4.64 (d, 1H, J1,2 9.5 Hz,
H-1), 4.24–4.15 (m, 2H, H-6a, H-6b), 3.76 (ddd, 1H,
J5,6a 3.1 Hz, J5,6b 3.6 Hz, H-5), 2.11, 2.06, 2.04, 2.02 (s,
12H, acetyl CH3); 13C NMR (CDCl3): l 170.3, 170.0,
169.0, 168.8 (acetyl CO), 108.3 (CN), 88.6 (C-1), 73.9,
72.6, 69.7, 67.3 (C-2, C-3, C-4, C-5), 61.4 (C-6), 20.5,
20.3, 20.2 (acetyl CH3). Anal. Calcd for C29H38N2O13
(702.63): C, 49.57; H, 5.45; N, 3.99. Found: C, 49.52;
H, 5.49; N, 3.84.
1
tified using the H and 13C NMR chemical shift values
known from the literature.10
Bis(2,3,4 - tri - O - acetyl - i - D - xylopyranosyl)carbodi-
imide (13). Prepared from 7 (0.30 g, 1.00 mmol) accord-
ing to General Procedure A; Yield: 0.18 g (65%),
colourless crystalline product; mp 133–134 °C (iPr2O),
lit.11 mp 139 °C; [h]D −69.9° (c 1.0, CHCl3); lit.11 [h]D
−116.9° (c 1.0, CHCl3); w (KBr): 2153 (NꢀCꢀN) and
1
1760 (OAc) cm−1. H NMR (CDCl3): l 5.10 (dd, 1H,
J3,4 9.5 Hz, H-3), 4.93 (ddd, 1H, J4,5 5.1 Hz, H-4), 4.82
(dd, 1H, J2,3 9.0 Hz, H-2), 4.65 (d, 1H, J1,2 8.4 Hz,
H-1), 4.10 (dd, 1H, J5,5a 11.5 Hz, H-5a), 3.33 (dd, 1H,
J4,5b 10.0 Hz, H-5b), 2.00, 1.98, 1.97 (s, 9H, acetyl
CH3); 13C NMR (CDCl3): l 169.8, 169.5, 169.1 (acetyl
CO), 137.2 (NꢀCꢀN), 84.4 (C-1), 72.0, 71.8, 68.3 (C-2,
C-3, C-4), 64.1 (C-5), 20.4 (acetyl CH3); 15N NMR
(CDCl3): l 77.2 (NꢀCꢀN).
The second fraction (Rf 0.41) gave 0.17 g (26%) of
cyanoguanidine 22. Mp 240–242 °C, [h]D −19.8° (c
1.1, CHCl3); w (KBr): 3409 (NH), 2195 (CN), 1749
(OAc) and 1610 (CꢀN) cm−1 1H NMR (CDCl3): l
.
6.68 (m, 1H, NH), 5.33 (Ct, 1H, J4,5 9.5 Hz, H-4), 5.06
(Ct, 1H, J2,3 9.5 Hz, H-2), 4.92 (Ct, 1H, J3,4 8.9 Hz,
H-3), 4.80 (dd, 1H, J1,2 10.0 Hz, JNH,1 6.8 Hz, H-1),
4.30 (dd, 1H, J6a,6b 12.6 Hz, H-6a), 4.17 (m, 1H, H-6b),
3.76 (ddd, 1H, J5,6a 4.7 Hz, J5,6b 2.6 Hz, H-5), 2.14,
2.12, 2.05, 2.04 (s, 12H, acetyl CH3); 13C NMR
(CDCl3): l 171.1, 170.3, 169.7, 169.3 (acetyl CO), 159.4
(guanidine), 115.0 (CN), 80.5 (C-1), 73.0, 72.2, 70.5,
67.4 (C-2, C-3, C-4, C-5), 61.5 (C-6), 20.5, 20.4 (acetyl
CH3). Anal. Calcd for C30H40N4O18 (744.67): C, 48.39;
H, 5.41; N, 7.52. Found: C, 48.23; H, 5.49; N, 7.44.
Bis(2,3,4-tri-O-acetyl-h-D-arabinopyranosyl)carbodi-
imide (14). Prepared from 8 (0.30 g, 1.00 mmol) accord-
ing to General Procedure A; Yield: 0.21 g (76%),
colourless crystalline product; mp 162–163 °C (EtOH–
iPr2O), [h]D −35.8° (c 1.1, CHCl3); w (KBr): 2151
1
(NꢀCꢀN) and 1748 (OAc) cm−1. H NMR (CDCl3): l
5.88 (d, 1H, J1,2 8.4 Hz, H-1), 5.33 (ddd, 1H, J4,5b 1.5
Hz, H-4), 5.14 (dd, 1H, J3,4 3.2 Hz, H-3), 5.10 (dd, 1H,
J2,3 10.0 Hz, H-2), 3.97 (dd, 1H, J4,5a 2.0 Hz, H-5a),
3.80 (dd, 1H, J5,5b 13.2 Hz, H-5b), 2.15, 2.08, 2.02 (s,
9H, acetyl CH3); 13C NMR (CDCl3): l 170.9, 170.2,
169.9 (acetyl CO), 140.7 (NꢀCꢀN), 79.8 (C-1), 70.9,
68.2, 68.1 (C-2, C-3, C-4), 65.3 (C-5), 20.5, 20.4, 20.2
(acetyl CH3). Anal. Calcd for C23H30N2O14 (558.50): C,
49.46; H, 5.41; N, 5.02. Found: C, 49.55; H, 5.30; N,
4.92.
N,N-Bis(2,3,4,6-tetra-O-acetyl-i-
syl)-cyanamide (23) and N1,N3-bis(2,3,4,6-tetra-O-ace-
tyl-i-
-galactopyranosyl)-N2-cyanoguanidine (24). Pre-
D-galactopyrano-
D
pared from 16 (0.78 g, 2.00 mmol) according to General
Procedure B; the first fraction (Rf 0.30) gave 0.29 g
(42%) of cyanamide 23 as colourless crystalline pro-
duct; mp 156–157 °C, [h]D +18.0° (c 1.0, CHCl3); w
1
(KBr): 2232 (N-CꢀN) and 1748 (OAc) cm−1. H NMR

1176
L. Ko6a´cs et al. / Carbohydrate Research 337 (2002) 1171–1178
(CDCl3): l 5.41 (m, 1H, H-4), 5.37 (dd, 1H, J2,3 10.0
Hz, H-2), 5.12 (dd, 1H, J3,4 2.7 Hz, H-3), 4.54 (d, 1H,
J1,2 9.5 Hz, H-1), 4.15 (dd, 1H, J5,6a 6.3 Hz, J6a,6b 11.6
Hz, H-6a), 4.09 (dd, 1H, J5,6b 6.8 Hz, H-6b), 3.95 (ddd,
1H, J4,5 1.6 Hz, H-5), 2.21, 2.08, 2.06, 2.00 (s, 12H,
acetyl CH3); 13C NMR (CDCl3): l 169.9, 169.8, 169.6,
168.5 (acetyl CO), 108.7 (CN), 88.7 (C-1), 72.5, 70.8,
66.9, 66.6 (C-2, C-3, C-4, C-5), 61.0 (C-6), 20.2 (acetyl
CH3). Anal. Calcd for C29H38N2O13 (702.63): C, 49.57;
H, 5.45; N, 3.99. Found: C, 49.62; H, 5.58; N, 3.87.
The second fraction (Rf 0.20) gave 0.14 g (20%) of
cyanoguanidine 24. Mp 168–170 °C, [h]D −32.5° (c
1.0, CHCl3); w (KBr): 3411 (NH), 2186 (CN), 1749
Calcd for C24H32N4O14 (600.54): C, 48.00; H, 5.37; N,
9.33. Found: C, 48.15; H, 5.43; N, 9.21.
N,N-Bis(2,3,4-tri-O-acetyl-i-
D
-ribopyranosyl)cyana-
-ribopy-
mide (27) and N1,N3-bis(2,3,4-tri-O-acetyl-i-
D
ranosyl)-N2-cyanoguanidine (28). Prepared from 18
(0.64 g, 2.00 mmol) according to General Procedure B;
The first fraction (Rf 0.60) gave 0.28 g (51%) of
cyanamide 27 as colourless crystalline product. Mp:
175–177 °C, [h]D −35.1° (c 1.0, CHCl3); w (KBr): 2228
(N-CꢀN) and 1752 (OAc) cm−1. H NMR (CDCl3): l
1
5.73 (m, 1H, H-3), 5.46 (m, 1H, H-4), 5.03 (dd, 1H, J2,3
2.4 Hz, H-2), 4.50 (d, 1H, J1,2 8.9 Hz, H-1), 3.99 (dd,
1H, J4,5a 5.3 Hz, J5,5b 11.0 Hz, H-5a), 3.80 (Ct, 1H, J4,5b
10.5 Hz, H-5b), 2.21, 2.07, 2.03 (s, 9H, acetyl CH3); 13C
NMR (CDCl3): l 169.5, 169.1, 168.6 (acetyl CO), 109.4
(CN), 84.3 (C-1), 67.8, 67.0, 65.3 (C-2, C-3, C-4), 62.8
(C-5), 20.5, 20.3, 20.2 (acetyl CH3). Anal. Calcd for
C23H30N2O14 (558.50): C, 49.46; H, 5.41; N, 5.02.
Found: C, 49.33; H, 5.52; N, 4.89.
(OAc) and 1615 (CꢀN) cm−1 1H NMR (CDCl3): l
.
6.74 (m, 1H, NH), 5.42 (dd, 1H, J4,5 1.0 Hz, H-4), 5.13
(dd, 1H, J3,4 3.2 Hz, H-3), 5.07 (dd, 1H, J1,2 8.9 Hz, J2,3
10.0 Hz, H-3), 4.75 (m, 1H, H-1), 4.20–4.05 (m, 3H,
H-5, H-6a, H-6b), 2.11, 2.09, 2.04, 1.97 (s, 12H, acetyl
CH3); 13C NMR (CDCl3): l 171.3, 170.2, 169.7, 169.5
(acetyl CO), 159.8 (guanidine), 115.2 (CN), 81.0 (C-1),
72.2, 70.2, 67.9, 66.9 (C-2, C-3, C-4, C-5), 61.0 (C-6),
20.6, 20.5, 20.4, 20.3 (acetyl CH3). Anal. Calcd for
C30H40N4O18 (744.67): C, 48.39; H, 5.41; N, 7.52.
Found: C, 49.46; H, 5.33; N, 7.60.
The second fraction (Rf 0.46) was 0.06 g (11%) of
cyanoguanidine 28. Mp: 215–217 °C, [h]D −16.6° (c
1.0, CHCl3); w (KBr): 3400 (NH), 2188 (CN), 1759
(OAc) and 1616 (CꢀN) cm−1 1H NMR (CDCl3): l
.
6.71 (bs, 1H, NH), 5.68 (Ct, 1H, J2,3 2.8 Hz, J3,4 2.7
Hz, H-3), 5.03 (m, 1H, H-1), 4.99 (m, 1H, H-4), 4.94
(dd, 1H, J1,2 9.2 Hz, H-1), 3.90–3.80 (m, 2H, H-5a,
H-5b), 2.10, 2.05, 2.00 (s, 9H, acetyl CH3); 13C NMR
(CDCl3): l 170.6, 169.7, 169.4 (acetyl CO), 160.5
(guanidine), 115.5 (CN), 78.3 (C-1), 68.1 (C-2), 68.0
(C-3), 66.0 (C-4), 62.3 (C-5), 20.8, 20.7, 20.5 (acetyl
CH3). Anal. Calcd for C24H32N4O14 (600.54): C, 48.00;
H, 5.37; N, 9.33. Found: C, 47.88; H, 5.32; N, 9.21.
N,N-Bis(2,3,4-tri-O-acetyl-i-
D
-xylopyranosyl)cyana-
-xylopy-
mide (25) and N1,N3-bis(2,3,4-tri-O-acetyl-i-
D
ranosyl)-N2-cyanoguanidine (26). Prepared from 17
(0.64 g, 2.00 mmol) according to General Procedure B;
The first fraction (Rf 0.67)gave 0.24 g (43%) of
cyanamide 25 as colourless crystalline product. Mp:
170–172 °C, [h]D −62.8° (c 1.1, CHCl3); w (KBr): 2232
(N-CꢀN) and 1758 (OAc) cm−1. H NMR (CDCl3): l
1
5.24 (t, 1H, J3,4 9.0 Hz, H-3 or H-2), 5.06 (t, 1H, J2,3 9.0
Hz, H-2 or H-3), 4.96 (ddd, 1H, H-4), 4.51 (d, 1H, J1,2
9.0 Hz, H-1), 4.15 (dd, 1H, J4,5a 5.3 Hz, H-5a), 3.35
(dd, 1H, J5,5b 11.6 Hz, J4,5b 9.7 Hz, H-5b), 2.04, 2.03 (s,
9H, acetyl CH3); 13C NMR (CDCl3): l 169.8, 169.4,
168.7 (acetyl CO), 108.4 (CN), 87.7 (C-1), 71.7, 69.1,
67.9 (C-2, C-3, C-4), 64.0 (C-5), 20.3, 20.2 (acetyl CH3);
15N NMR (CDCl3): l 196.3, 45.8 (N-CN). MALDI-
TOF MS (558.50): 597.07 [M+K]+, 581.10 [M+Na]+
. Anal. Calcd for C23H30N2O14 (558.50): C, 49.46; H,
5.41; N, 5.02. Found: C, 49.35; H, 5.35; N, 4.87.
The second fraction (Rf 0.51) gave 0.17 g (29%) of
cyanoguanidine 26. Mp: 122–123 °C, [h]D −40.6° (c
1.0, CHCl3); w (KBr): 3406 (NH), 2190 (CN), 1756
N-(2,3,4-Tri-O-acetyl-h-
mide (29) and N,N-bis(2,3,4-tri-O-acetyl-h-
D
-arabinopyranosyl)cyana-
-arabino-
D
pyranosyl)cyanamide (30). Prepared from 19 (0.64 g,
2.00 mmol) according to General Procedure B; The first
fraction (Rf 0.63) gave 0.11 g (18%) of cyanamide 29 as
colourless crystalline product. Mp 189–190 °C [h]D
+30.9° (c 1.1, CHCl3); w (KBr): 3400 (NH), 2196 (CN)
1
and 1749 (OAc) cm−1. H NMR (CDCl3): l 5.29 (bs,
1H, NH), 5.27 (m, 1H, H-4), 5.08 (dd, 1H, J2,3 10.0 Hz,
J3,4 3.4 Hz, H-3), 5.04 (dd, 1H, J1,2 10.1 Hz, H-2), 4.40
(t, 1H, JNH,1 8.5 Hz, H-1), 4.03 (dd, 1H, J4,5a 2.2 Hz,
J5,5b 13.5 Hz, H-5a), 3.72 (dd, 1H, J4,5b 1.3 Hz, H-5b),
2.12, 2.10, 1.99 (s, 9H, acetyl CH3); 13C NMR (CDCl3):
l 170.8, 170.1, 169.8 (acetyl CO), 112.6 (CN), 85.9
(C-1), 70.1 (C-3), 68.2 (C-2), 67.6 (C-4), 65.7 (C-5),
20.7, 20.6, 20.5 (acetyl CH3). Anal. Calcd for
C12H16N2O7 (300.24): C, 48.00; H, 5.37; N, 9.33.
Found: C, 48.12; H, 5.42; N, 9.27.
(OAc) and 1614 (CꢀN) cm−1 1H NMR (CDCl3): l
.
6.73 (d, 1H, JNH,1 8.2 Hz, NH), 5.24 (Ct, 1H, J2,3 9.2,
Hz J3,4 9.7 Hz, H-3), 4.92 (ddd, 1H, J4,5ab 5.5 Hz, J4,5b
10.0 Hz, H-4), 4.88 (t, 1H, J1,2 9.0 Hz, H-2), 4.80 (t, 1H,
H-1), 4.05 (dd, 1H, J5,5b 11.7 Hz, H-5a), 3.46 (Ct, 1H,
H-5b), 2.04, 2.00, 1.99 (s, 9H, acetyl CH3); 13C NMR
(CDCl3): l 171.0, 169.7 (acetyl CO), 159.5 (guanidine),
115.2 (CN), 80.8 (C-1), 71.5 (C-3), 70.3 (C-2), 68.3
(C-4), 63.7 (C-5), 20.6, 20.5, 20.5 (acetyl CH3).
MALDI-TOF MS (600.54): 623.05 [M+Na]+. Anal.
The second fraction (Rf 0.41) was 0.30 g (53%) of
bis(glycosyl)cyanamide 30, colourless crystalline
product; mp 203–205 °C (EtOH–iPr2O), [h]D +59.8°
(c 1.1, CHCl3); w (KBr): 2230 (N-CꢀN) and 1742 (OAc)
1
cm−1. H NMR (CDCl3): l 5.46 (t, 1H, J2,3 8.9 Hz,
H-2), 5.23 (m, 1H, H-4), 5.11 (dd, 1H, J3,4 3.2 Hz, H-3),

L. Ko6a´cs et al. / Carbohydrate Research 337 (2002) 1171–1178
1177
4.50 (d, 1H, J1,2 8.9 Hz, H-1), 4.06 (dd, 1H, J4,5a 2.6 Hz,
J5,5b 13.2 Hz, H-5a), 3.67 (m, 1H, H-5b), 2.21, 2.07,
2.04 (s, 9H, acetyl CH3); 13C NMR (CDCl3): l 170.0,
169.7, 168.6 (acetyl CO), 109.6 (CN), 88.0 (C-1), 70.4,
67.5, 67.1 (C-2, C-3, C-4), 65.2 (C-5), 20.6, 20.3 (acetyl
CH3). Anal. Calcd for C23H30N2O14 (558.50): C, 49.46;
H, 5.41; N, 5.02. Found: C, 49.68; H, 5.55; N, 4.96.
H-1, H-6a, H-6a%), 4.20–4.05 (m, 2H, H-6b, H-6b%),
3.84 (m, 2H, H-5, H-5%), 3.61 (m, 1H, H-2), 3.55 (s, 3H,
OCH3), 2.11, 2.08, 2.04, 2.03 (s, 21H, acetyl CH3); 13C
NMR (CDCl3): l 184.6 (thiourea), 170.9, 170.6, 170.5,
169.7, 169.5 169.2 (acetyl CO), 101.9 (C-1), 82.9 (C-1%),
73.2, 72.7, 71.6, 70.5, 68.0, 67.8 (C-3, C-4, C-5, C-2%,
C-3%, C-4%, C-5%), 61.7, 61.5 (C-6, C-6%), 58.2 (C-2), 57.9
(OCH3), 20.5, 20.4 (acetyl CH3). Anal. Calcd for
C28H40N2O17S (708.70): C, 47.45; H, 5.69; N, 3.95.
Found: C, 47.52; H, 5.55; N, 3.89.
N,N-Bis(2,3,4-tri-O-acetyl-h-D-lyxopyranosyl)cyana-
mide (31).—Prepared from 20 (0.64 g, 2.00 mmol)
according to General Procedure B; Yield: 0.32 g (58%),
colourless crystalline product; mp 195–197 °C, [h]D
−51.5° (c 1.0, CHCl3); w (KBr): 2228 (N-CꢀN) and
Methyl 3,4,6-tri-O-acetyl-2-deoxy-2-(N%-methylcar-
bodiimido)-i- -glucopyranoside (36).—Compound 34
D
1
1752 (OAc) cm−1. H NMR (CDCl3): l 5.49 (t, 1H,
(1.99 g, 5.1 mmol) and 3.25 g (1.5 mmol) of HgO were
stirred in a mixture of 69 mL of CHCl3 and 69 mL of
water for 30 min at room temperature. The organic
layer was separated from the water, dried on CaCl2 and
filtrated. After evaporation of the solvent, the crude
product was purified by crystallisation (EtOAc–hex-
ane). Yield: 1.14 g (63%), colourless crystalline product,
mp 72–73 °C, [h]D +2.9° (c 1.0, CHCl3); w (KBr): 2148
J2,3 3.3 Hz, H-2), 5.35 (dd, 1H, J3,4 9.5 Hz, H-3), 4.82
(d, 1H, J1,2 3.3 Hz, H-1), 4.79 (dd, 1H, J4,5a 5.0 Hz,
J5a,5b 13.0 Hz, H-5a), 4.01 (dd, 1H, J4,5b 10.5 Hz, H-5b),
3.93 (m, 1H, H-4), 2.21, 2.16, 2.04 (s, 9H, acetyl CH3);
13C NMR (CDCl3): l 169.5, 168.8, 168.7 (acetyl CO),
110.7 (CN), 84.5 (C-1), 68.0, 67.4, 66.0 (C-2, C-3, C-4),
64.8 (C-5), 20.7, 20.5, 20.3 (acetyl CH3). Anal. Calcd
for C23H30N2O14 (558.50): C, 49.46; H, 5.41; N, 5.02.
Found: C, 49.52; H, 5.31; N, 5.15.
1
(NꢀCꢀN) and 1754 (OAc) cm−1. H NMR (CDCl3): l
4.97 (t, 1H, J3,4 9.5 Hz, H-3), 4.90 (t, 1H, J4,5 9.5 Hz,
H-4), 4.22 (dd, 1H, J5,6a 4.7 Hz, H-6a), 4.17 (d, 1H, J1,2
7.9 Hz, H-1), 4.04 (dd, 1H, J5,6b 1.6 Hz, J6,6b 12.1 Hz,
H-6b), 3.62 (ddd, 1H, H-5), 3.50 (s, 3H, OCH3), 3.36
(dd, 1H, J2,3 9.5 Hz, H-2), 2.88 (s, 3H, NCH3), 1.99,
1.93 (s, 9H, acetyl CH3); 13C NMR (CDCl3): l 170.4,
169.9, 169.4 (acetyl CO), 139.8 (NꢀCꢀN), 103.0 (C-1),
73.9, 71.5, 68.3 (C-3, C-4, C-5), 62.0 (C-6), 60.0 (C-2),
57.3 (OCH3), 32.1 (NCH3), 20.5, 20.4 (acetyl CH3).
Anal. Calcd for C15H22N2O8 (358.35): C, 50.28; H, 6.19;
N, 7.82. Found: C, 50.35; H, 6.05; N, 7.76.
Methyl
ioureido)-i-
O-acetyl-2-amino-2-deoxy-b-
3,4,6-tri-O-acetyl-2-deoxy-2-(N%-methylth-
-glucopyranoside (34).—Methyl 3,4,6-tri-
-glucopyranoside (32,
D
D
0.96 g, 3 mmol) and 0.22 g (3 mmol) of methylisothio-
cyanate were stirred at 80 °C in 6 mL EtOAc for 2 h.
After evaporation of the solvent, the crude product
(0.94 g) was purified by crystallisation (benzene–hex-
ane). Yield: 0.70 g (60%), mp 157–158 °C, colourless
crystalline product, [h]D +43.7° (c 1.0, CHCl3); w
(KBr): 3358, 1504, 1372 (thiourea) and 1748 (OAc)
cm−1. 1H NMR (CDCl3): l 6.86 (m, 1H, NH), 6.20 (m,
1H, NH), 5.15 (dd, 1H, J3,4 7.9 Hz, H-4), 5.11 (dd, 1H,
J2,3 9.0 Hz, H-3), 4.36 (d, 1H, J1,2 8.4 Hz, H-1), 4.31
(dd, 1H, J5,6a 4.7 Hz, J6a,6b 12.6 Hz, H-6a), 4.14 (dd,
1H, J5,6b 2.6 Hz, H-6b), 3.70 (ddd, 1H, J4,5 9.5 Hz,
H-5), 3.67 (m, 1H, H-2), 3.57 (s, 3H, OCH3), 3.07 (d,
3H, JNH,Me 3.3 Hz, NHMe), 2.10, 2.05 (s, 9H, acetyl
CH3); 13C NMR (CDCl3): l 180.8 (thiourea), 170.9,
170.4, 169.1 (acetyl CO), 104.6 (C-1), 75.0, 71.4, 67.9
(C-3, C-4, C-5), 61.9 (C-6), 58.6 (C-2), 57.0 (OCH3),
55.6 (NCH3), 20.5, 20.4 20.3 (acetyl CH3). Anal. Calcd
for C15H24N2O8S (392.43): C, 45.91; H, 6.16; N, 7.14.
Found: C, 46.34; H, 6.14; N: 6.81.
Methyl
tetra-O-acetyl-i-
3,4,6-tri-O-acetyl-2-deoxy-2-[N%-(2,3,4,6-
-glucopyranosyl)carbodiimido]-i-D-
D
glucopyranoside (37).—Prepared from 35 (1.42 g, 2.0
mmol) according to the previous procedure. Yield: 1.02
g (76%), colourless crystalline product, mp 141–142 °C,
[h]D +6.1° (c 1.0, CHCl3); w (KBr): 2148 (NꢀCꢀN) and
1
1750 (OAc) cm−1. H NMR (CDCl3): l 5.16 (Ct, 1H,
J4%,5% 8.5 Hz, H-4%), 5.10 (t, 1H, J4,5 9.5 Hz, H-4), 5.06
(dd, 1H, J3,4 9.5 Hz, H-3), 4.96 (t, 1H, J3%,4% 9.5 Hz,
H-3%), 4.91 (Ct, 1H, J2%,3% 9.5 Hz, H-2%), 4.69 (d, 1H, J1,2
8.9 Hz, H-1%), 4.32 (d, 1H, J1,2 8.4 Hz, H-1), 4.28 (dd,
1H, J5,6 4.5 Hz, J6a,6b 12.3 Hz, H-6a), 4.21 (dd, 1H,
J5%,6a% 2.1 Hz, J6a%,6b% 12.1 Hz, H-6a%), 4.16 (dd, 1H, J5%,6b%
4.5 Hz, H-6b%), 4.11 (dd, 1H, J5,6b 2.1 Hz, H-6b), 3.73
(ddd, 2H, H-5, H-5%), 3.57 (s, 3H, OCH3), 3.50 (dd, 1H,
J2,3 10.0 Hz, H-2), 2.09, 2.07, 2.06, 2.02, 2.00, 1.99 (s,
21H, acetyl CH3); 13C NMR (CDCl3): l 170.4, 169.9,
169.8, 169.4, 169.1 (acetyl CO), 137.6 (NꢀCꢀN), 102.4
(C-1), 84.2 (C-1%), 73.7, 71.5, 68.3 (C-3, C-4, C-5), 73.3,
72.7, 72.3, 67.8 (C-2%, C-3%, C-4%, C-5%), 61.7, 61.3 (C-6,
C-6%), 59.8 (C-2), 57.1 (OCH3), 20.5, 20.4 (acetyl CH3).
Anal. Calcd for C28H38N2O17 (674.62): C, 49.85; H,
5.68; N, 4.15. Found: C, 50.01; H, 5.52; N, 4.17.
Methyl
tetra-O-acetyl-i-
3,4,6-tri-O-acetyl-2-deoxy-2-[N%-(2,3,4,6-
-glucopyranosyl)thioureido]-i- -glu-
D
D
copyranoside (35).—Prepared from 32 (1.60 g, 5 mmol)
and 33 (1.94 g, 5 mmol) according to the previous
procedure. Yield: 2.96 g (84%), colourless crystalline
product, mp 191–192 °C (dry EtOH), [h]D +5.9° (c
1.0, CHCl3); w (KBr): 3372, 1562, 1366 (thiourea) and
1
1754 (OAc) cm−1. H NMR (CDCl3): l 6.53 (m, 1H,
NH), 5.81 (m, 1H, NH), 5.35 (dd, 1H, J3%,4% 8.9 Hz, J4%,5%
10.0 Hz, H-4%), 5.20–5.05 (m, 4H, H-3, H-4, H-2%,
H-3%), 5.01 (t, 1H, J1%,2% 9.5 Hz, H-1%), 4.45–4.25 (m, 3H,

1178
L. Ko6a´cs et al. / Carbohydrate Research 337 (2002) 1171–1178
12. Ferna´ndez J. M. G.; Mellet C. O.; Pe´rez V. M. D.;
Acknowledgements
Fuentes J.; Kova´cs J.; Pinte´r I. Carbohydr. Res. 1997,
304, 261–270.
This research was supported by a grant from the
National Science Research Foundation (no. OTKA
T32124) in Hungary.
13. Ferna´ndez J. M. G.; Mellet C. O.; Pe´rez V. M. D.;
Fuentes J.; Kova´cs J.; Pinte´r I. Tetrahedron Lett. 1997,
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14. Gyo¨rgydea´k Z.; Szila´gyi L.; Paulsen H. J. Carbohydr.
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2
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