Towards sucrose macrocycles with higher symmetry via a 'click chemistry' route

Article abstract of DOI:10.1055/s-2008-1032198

Chiral macrocycles containing the sucrose skeleton were prepared by a 'click chemistry' route. The substrate for the Huisgen reaction was obtained from sucrose in eight steps. The 1,3-dipolar cycloaddition yielded the intramolecular as well as the C₂-symmetric macrocycles. Optimization of the reaction conditions allowed the preparation of both types of adducts with high selectivity and in good yields. Georg Thieme Verlag Stuttgart.

Full text of DOI:10.1055/s-2008-1032198

PAPER
913
Towards Sucrose Macrocycles with Higher Symmetry via a ‘Click Chemistry’
Route
Towards
S
ucr
o
ł
se Ma
a
c
rocycles
w
w
ith
H
igher Symm
o
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland
Fax +48(22)6326681; E-mail: sljar@icho.edu.pl
Received 16 November 2007; revised 11 December 2007
OH
Abstract: Chiral macrocycles containing the sucrose skeleton were
6
OR
1'
prepared by a ‘click chemistry’ route. The substrate for the Huisgen
OH
O
Gluc
RO
reaction was obtained from sucrose in eight steps. The 1,3-dipolar
cycloaddition yielded the intramolecular as well as the C2-symmet-
ric macrocycles. Optimization of the reaction conditions allowed
the preparation of both types of adducts with high selectivity and in
good yields.
O
Fruc
6'
O
RO
RO
OR
OR
1. R = H
ref. 7
Key words: sucrose, receptors, complexation, click chemistry
2. R = Bn
ref. 4,8
Sucrose, an inexpensive raw material, is available in more
than 140 million tons per year; most of it is consumed on
the food market.1 This chemical is very demanding to
work with, because of its very poor solubility in most or-
ganic solvents, the presence of eight hydroxy groups that
are difficult to differentiate, and the high sensitivity of the
glycosidic bond in acidic media. However, this disaccha-
ride is also a subject of interest as a starting material for
the preparation of fine chemicals,2–4 as well as biodegrad-
able polymers or surfactants.5 Recently, a biocatalytic ap-
proach to sucrose analogues was published.6
X
O
O
6
6'
Gluc Fruc
X = O, N
Scheme 1 Modification of sucrose at the terminal positions
6- and 6¢-hydroxy groups in compound 2. This was
achieved using tert-butyldiphenylsilyl chloride as the pro-
tecting agent. Reaction of the diol 2 with 1.1 equivalents
tert-butyldiphenylsilyl chloride afforded 70% of the alco-
hol 3,11 which was readily converted into the correspond-
ing azide 5 in two steps. Removal of the silyl protection
with fluoride ion afforded the alcohol with the 6¢-hydroxy
group free, which was easily converted into the desired
synthon 6 by reaction with propargyl bromide under stan-
dard conditions (Scheme 2).
As a part of an on-going program we have elaborated a
convenient route to 1¢,2,3,3¢,4,4¢-hexa-O-benzylsucrose7
(2), useful starting material for the preparation of deriva-
tives modified at the terminal (C6, C6¢) positions. The diol
2 served also as the starting material for the preparation of
analogues of crown ethers with an incorporated sucrose
unit (e.g., Scheme 1).4,8 Such compounds might be, even-
tually, applied as chiral receptors for the recognition of
quaternary ammonium salts (derived from amines, amino
acids, etc.).
The cycloaddition reaction performed in the presence of
copper(I) iodide in acetonitrile at room temperature af-
forded a mixture of products: the C2-symmetric macrocy-
cle 7 (m/z = 1890) and a C1 adduct 8 (m/z = 945) (Table 1,
entry 1).
To improve the complexing properties of such receptors
we decided to synthesize analogues possessing a twofold
axis of symmetry, containing two sucrose moieties, linked
by a proper function. The dipolar alkyne-azide cycloaddi-
tion (so-called ‘click reaction’9) was chosen as a tool to
prepare such C2-symmetric compounds. The obvious ad-
vantage of this approach is the simplicity and feasibility of
the method, which has been applied to the preparation of
various derivatives for biochemical, supramolecular, and
material chemistry purposes.10
Spectroscopic data of the latter 8 strongly pointed at the
presence of two regioisomers. This assumption was sup-
ported by the 13C NMR data in which two signals for the
C1 (glucose part) were seen at d = 91.48 and 91.44, re-
spectively. Also in the H NMR spectrum of this C1 ad-
duct two signals, which could be connected with the
1
triazole ring, at d = 8.22 and 7.71 were seen.
The synthetic approach to the substrate 6, which is suit-
able for the cycloaddition, required differentiation of the
Based on the report by Dondoni and Marra12 we may pos-
tulate that both regioisomeric adducts with 1,4- and 1,5-
substituted triazole ring were formed under the cycliza-
tion conditions. The corresponding literature data for the
1,4- and 1,5-sugar-based triazoles 9 and 10 are d = 8.00
and 7.70, respectively (see Figure 1).14
SYNTHESIS 2008, No. 6, pp 0913–0916
x
x
.
x
x
.2
0
0
8
Advanced online publication: 28.02.2008
DOI: 10.1055/s-2008-1032198; Art ID: P13407SS
© Georg Thieme Verlag Stuttgart · New York

914
S. Jarosz et al.
PAPER
OH
OBn
OBn
OBn
6
O
O
BnO
BnO
OTBDPS
N
BnO
BnO
N
TBDPSCl, DIPEA,
O
Gluc
N
N
BnO
O
N
H
N
2
OBn
OBn
6'
Fruc
CH2Cl2, DMAP, 65%
O
Ph
9
H
10
BnO
Ph
BnO
OBn
OBn
δ = 8.00 ppm
δ = 7.70 ppm
3
1,4-triazole
1,5-triazole
Figure 1 Sugar-based triazoles14
MsCl, CH2Cl2,
Et3N, 99%
OTBDPS
R
6
6'
As reported recently, reaction of the sugar derivatives 11
and 12 under the Sharpless conditions afforded, the ‘anti-
Sharpless’ adduct 13, resulting from intramolecular reac-
tion of 11, structure of which was confirmed by X-ray
crystal structure analysis (Scheme 3).14 All other cycload-
ditions reported by these authors yielded, however, the ex-
pected Sharpless adducts.
Gluc Fruc
4, R = OMs
5, R = N3
NaN3, DMF, 85%
X
O
O
Cu(I)
O
O
N3
O
O
for 11
1. Bu4NF, 95%
6
N
6'
O
O
N3
N
N
2. propargyl bromide, NaH,
DMF, 85%
O
Gluc Fruc
13
11 X = H2
12 X = O
for 12
1,5-adduct
(X-ray crystal structure)
6
Scheme 2 Preparation of the sucrose monomer for the 1,3-dipolar
cycloaddition
adducts with the C2 symmetry
with the 1,4-triazole ring
6
Scheme 4 Formation of the unexpected 1,5-adduct during cycliza-
conditions
see Table 1
tion of the sugar derivatives16
OBn
The reaction shown in Scheme 2, leading to sucrose-
based macrocycles, required optimization. A series of ex-
periments (results are shown in Table 1) allowed us to
elaborate the proper conditions for the preparation of ei-
ther ‘monomeric’ C1 or dimeric C2 adducts.
BnO
BnO
BnO
O
OBn
N
N
N
O
O
OBn
O
OBn
O
BnO
O
OBn
Thus, when this 1,3-dipolar cycloaddition was performed
in acetonitrile as a solvent at elevated temperature and at
a low concentration of 6 (Table 1, entry 3) the monomeric
adduct 8 was formed in 48% yield (according to NMR
data it was a mixture of the regioisomeric 1,4- and 1,5-ad-
ducts). However, when the concentration of the substrate
was high, the overall yield of the products was significant-
ly lower (entry 2). Very interesting are the reactions per-
formed in toluene at elevated temperature (entries 4 and
5). In the absence of the catalyst only the C2-symmetric
adduct 7 was obtained in very reasonable yield (entry 4),
while reaction performed in the presence of copper iodide
afforded predominantly the monomeric adduct 8.15
O
O
N
N
BnO
N
OBn
OBn
7
+
N
N
N
N
N
N
O
O
O
6
6
BnO
O
BnO
6'
6'
O
O
+
BnO
BnO
O
O
BnO
BnO
BnO
8a
OBn
BnO
8b
OBn
OBn
OBn
Use of copper(I) cyanide instead of copper(I) iodide re-
quired a longer reaction time for completion (entries 6 and
7). On the other hand, copper(I) bromide proved to be the
most effective catalyst for the reaction in terms of reaction
time, however the selectivity and the yields of the prod-
ucts were lower than for copper(I) iodide (entry 8).16
Scheme 3 Alkyne-azide cycloaddition of compound 6
Although the presence of the 1,5-adduct is rather unex-
pected according to the widely accepted mechanism of
this copper-catalyzed 1,3-dipolar cycloaddition,9,13 there
are reports on the formation of such compounds under
these conditions.
The 1,3-dipolar cycloaddition of suitable protected su-
crose derivatives with the azide function at the C6 (glu-
cose part) position and the propargyl function at the C6¢
Synthesis 2008, No. 6, 913–916 © Thieme Stuttgart · New York

PAPER
Towards Sucrose Macrocycles with Higher Symmetry
915
Table 1 Optimization of the Conditions of the Cycloadditiona
Entry
Concn (mmol/L) Solvent
Catalyst
Temp (°C)
Time (h)
Yield (%)
8a/8b
7
1
2
3
4
5
6
7
8
4.23
16.93
2.12
3.81
3.97
2.12
2.12
2.12
MeCN
MeCN
MeCN
toluene
toluene
MeCN
toluene
toluene
CuI
r.t.
r.t.
r.t.
80
80
r.t.
80
r.t.
48
24
40
5
CuI
23
trace
3
CuI
24
48
none
CuI
240
48
trace
25
45
10
trace
5
CuCN
CuCN
CuBr
96
23
120
16
20
30
3
a 1.1 equiv of DIPEA was used as a base in each entry.
column chromatography (hexane–EtOAc, 6:1) to give 5 (425 mg,
86%) as a yellowish oil.
‘end’ (fructose part) led to monomeric and dimeric (with
the C2 symmetry) receptors. It was possible to obtain ei-
ther the monomeric or dimeric product in very good yield 1H NMR (500 MHz): d = 7.69–7.72 [m, 10 H, Si(t-Bu)(C6H5)2],
7.20–7.42 (m, 30 H, HBn), 5.83 (d, J1,2 = 3.66 Hz, 1 H, H1), 2.90–
4.90 (Hdisaccharide, CH2Ph), 1.07 [s, 9 H, C(CH3)3].
(up to 50%) depending on the reaction conditions. Two
monomeric regioisomers were formed (the 1,4- and 1,5-
13C NMR (125 MHz): d = 138.8, 138.5, 138.3, 138.2, 138.1, 137.9
(6 Cq OCH2Ph), 135.7, 135.5 (2 Cq in TBDPS), 104.5 (C2¢), 89.2
(C1), 84.0, 81.8, 81.6, 80.9, 80.1, 78.0, 70.0 (C2, C3, C3¢, C4, C4¢,
C5, C5¢), 75.4, 74.8, 73.5, 73.3, 72.6, 72.1, 71.8, 64.2, 51.2 (C1¢,
C6, C6¢, 6 OCH2Ph), 26.9 [C(CH3)3], 19.3 [C(CH3)3].
triazole adducts) under these conditions, which, although
unexpected in the copper(I) iodide catalyzed reaction, is
in agreement with the recent literature data. Further work
on the synthesis of such sucrose receptors and their appli-
cation for the complexation of chiral amines and amino
acids is in progress.
MS (ESI): m/z = 1168.8 [M(C70H75N3O10Si) + Na]+.
6-Azido-1¢,2,3,3¢,4,4¢-hexa-O-benzyl-6-deoxysucrose
Compound 5 (420 mg, 0.367 mmol) was dissolved in THF (20 mL).
TBAF·3 H2O (300 mg, 0.952 mmol) was added and the mixture was
refluxed for 3 h. The solvent was then evaporated and the product
was purified by column chromatography (hexane–EtOAc, 3:1) to
give the title compound (330 mg, 99%) as a yellowish oil.
1H NMR (500 MHz): d = 7.20–7.35 (m, 30 H, HBn), 5.54 (d,
J1,2 = 3.45 Hz, 1 H, H1), 3.27–4.90 (Hdisaccharide, CH2Ph).
13C NMR (125 MHz): d = 138.6, 138.2, 138.12, 138.05, 138.00,
137.7 (6 Cq OCH2Ph), 103.99 (C2¢), 90.84 (C1), 83.66, 81.50,
81.18, 79.55, 79.47, 77.79, 70.79 (C2, C3, C3¢, C4, C4¢, C5, C5¢),
75.50, 75.08, 73.36, 73.35, 72.81, 72.61, 71.21, 61.29, 50.69 (C1¢,
C6, C6¢, 6 OCH2Ph).
NMR spectra were recorded with a Bruker AM 500 spectrometer
for solutions in CDCl3 (internal TMS). The resonances of the sec-
ondary carbon atoms were assigned by DEPT experiments. In the
1H NMR spectra, only signals not overlapping with others were cit-
ed. Mass spectra were recorded with an ESI/MS Mariner (PerSep-
tive Biosystem) mass spectrometer. Column chromatography was
performed on silica gel (Merck, 70–230 mesh). Organic solutions
were dried over anhydrous MgSO4.
1¢,2,3,3¢,4,4¢-Hexa-O-benzyl-6¢-O-(tert-butyldiphenylsilyl)-6-O-
(methylsulfonyl)sucrose (4)
Sucrose derivative 3 (120 mg, 0.107 mmol) was dissolved in
CH2Cl2 (10 mL). Et3N (2 mL) and DMAP (cat.) were added and the
mixture was stirred at r.t. Subsequently MsCl (0.1 mL) was added
dropwise (~10 min). After 4 h, H2O (20 mL) and CH2Cl2 (10 mL)
were added to the mixture. The aqueous layer was washed with
CH2Cl2 (2 × 10 mL). The combined organic layers were dried
(MgSO4) and filtered. The mixture was concentrated under reduced
pressure. The product was purified by column chromatography
(hexane–EtOAc, 4:1) to give 4 (127 mg, 99%) as a colorless oil.
MS (ESI): m/z = 930.7 [M(C54H57N3O10) + Na]+.
Anal. Calcd for C54H57N3O10·H2O: C, 70.04; H, 6.42; N, 4.54.
Found: C, 70.17; H, 6.36; N, 4.49.
6-Azido-1¢,2,3,3¢,4,4¢-hexa-O-benzyl-6-deoxy-6¢-propargyl-
sucrose (6)
6-Azido-1¢,2,3,3¢,4,4¢-hexa-O-benzyl-6-deoxysucrose (288 mg,
0.318 mmol) was dissolved in DMF (20 mL). NaH (40 mg, 1 mmol,
60% dispersion in mineral oils) was added and after 10 min propar-
gyl bromide (0.2 mL, 80% sol in toluene) was added dropwise. The
mixture was stirred at r.t. for 2 h. H2O (50 mL) and Et2O (25 mL)
were then added to the mixture. The aqueous layer was extracted
with Et2O (3 × 20 mL). The combined organic layers were washed
with H2O (30 mL) and brine (30 mL) and dried (MgSO4). Solvents
were then evaporated and the product was purified by column chro-
matography (hexane–EtOAc, 8:1) to give 6 (251 mg, 83%) as a yel-
low oil.
MS (ESI): m/z = 1221.3 [M(C71H78O13SSi) + Na]+.
6-Azido-1¢,2,3,3¢,4,4¢-hexa-O-benzyl-6¢-O-(tert-butyldiphenyl-
silyl)-6-deoxysucrose (5)
Sucrose derivative 4 (520 mg, 0.434 mmol) was dissolved in DMF
(30 mL). NaN3 (130 mg, 2 mmol) was added and the mixture was
stirred at 90 °C overnight. H2O (60 mL) and Et2O (40 mL) were then
added to the mixture. The aqueous layer was extracted with Et2O
(3 × 60 mL). The combined organic layers were washed with H2O
(60 mL) and brine (60 mL) and dried (MgSO4). The mixture was
concentrated under reduced pressure. The product was purified by
Synthesis 2008, No. 6, 913–916 © Thieme Stuttgart · New York

916
S. Jarosz et al.
PAPER
Legler, G.; Stütz, A. E. Carbohydr. Res. 1996, 287, 49.
(d) Lichtenthaler, F. W. Acc. Chem. Res. 2002, 35, 728.
(4) Review: Jarosz, S.; Mach, M. Eur. J. Org. Chem. 2002, 769;
and references therein.
1H NMR (500 MHz): d = 7.20–7.33 (m, 30 H, HBn), 5.73 (d, 1H,
J1,2 = 3.63 Hz, H1), 3.05–4.95 (Hdisaccharide, CH2Ph), 2.36 (t,
J1,3 = 2.35 Hz, 1 H, CH2C≡CH).
13C NMR (125 MHz): d = 138.8, 138.3, 138.2, 138.10, 138.06,
137.8 (6 Cq OCH2Ph), 104.57 (C2¢), 89.52 (C1), 83.75, 81.60,
81.57, 79.86, 79.31, 78.06, 70.79 (C2, C3, C3¢, C4, C4¢, C5, C5¢),
75.39, 74.87, 73.45, 73.04, 72.51, 72.15, 71.33, 70.35, 51.14 (C1¢,
C6, C6¢, 6 OCH2Ph), 79.50 (OCH2C≡CH), 74.82 (OCH2C≡CH),
58.36 (OCH2C≡CH).
(5) (a) Lichtenthaler, F. W. Carbohydr. Res. 1998, 313, 69. An
overview of sucrose chemistry is included in:
(b) Carbohydrates as Organic Raw Materials;
Lichtenthaler, F. W., Ed.; VCH: Weinheim, 1991.
(c) Lichtenthaler, F. W.; Mondel, S. Pure Appl. Chem. 1997,
69, 1853. (d) Descotes, G.; Gagnaire, J.; Bouchu, A.;
Thevenet, S.; Giry-Panaud, N.; Salanski, P.; Belniak, S.;
Wernicke, A.; Porwanski, S.; Queneau, Y. Polish J. Chem.
1999, 73, 1069.
MS (ESI): m/z = 968.4 [M(C57H59N3O10) + Na]+.
Anal. Calcd for C57H59N3O10: C, 72.36; H, 6.26; N, 4.44. Found: C,
72.33; H, 6.25; N, 4.39.
(6) Seibel, J.; Moraru, R.; Götze, S. Tetrahedron 2005, 61,
7081.
(7) Mach, M.; Jarosz, S.; Listkowski, A. J. Carbohydr. Chem.
2001, 20, 485.
(8) Jarosz, S.; Listkowski, A.; Lewandowski, B.; Ciunik, Z.;
Brzuszkiewicz, A. Tetrahedron 2005, 61, 8485.
(9) (a) Rostovtsev, V. V.; Green, L. G.; Fokin, V. V.; Sharpless,
K. B. Angew. Chem. Int. Ed. 2002, 41, 2596. (b) Tornoe, C.
M.; Christensen, C.; Meldal, M. J. Org. Chem. 2002, 67,
3057.
‘Click’ Cycloaddition; Typical Procedure
Sucrose derivative 6 (220 mg, 2.32 mmol) was dissolved in MeCN
(55 mL). CuI (13.4 mg, 0.07 mmol) and DIPEA (40 mL) were then
added. The mixture was stirred at r.t. for 48 h. The solvent was
evaporated and the product was purified by column chromatogra-
phy (hexane–EtOAc, 3:1 then 2:1).
C2-Symmetric Product 7
Yield: 10 mg (5%).
(10) Recent reviews: (a) Fournier, D.; Hoogenboom, R.;
Schubert, U. S. Chem. Soc. Rev. 2007, 36, 1369. (b) Moses,
J. E.; Moorhouse, A. D. Chem. Soc. Rev. 2007, 36, 1249.
Selected papers, biochemistry: (c) Alvarez, R.; Velazquez,
S.; San-Felix, A.; Aquaro, S.; De Clercq, E.; Perno, C.-F.;
Karlsson, A.; Balzarini, J.; Camarasa, M. J. J. Med. Chem.
1994, 37, 4185. (d) Genin, M. J.; Allwine, D. A.; Anderson,
D. J.; Barbachyn, M. R.; Emmert, D. E.; Garmon, S. A.;
Graber, D. R.; Grega, K. C.; Hester, J. B.; Hutchinson, D. K.;
Morris, J.; Reischer, R. J.; Ford, C. W.; Zurenko, G. E.;
Hamel, J. C.; Schaadt, R. D.; Stapert, D.; Yagi, B. H. J. Med.
Chem. 2000, 43, 953. Selected papers, carbohydrate
chemistry: (e) Kuijpers, B. H. M.; Groothuys, S.;
Keereweer, A. R.; Quaedflieg, P. J. L. M.; Blaauw, R. H.;
van Delft, F. L.; Rutjes, F. P. J. T. Org. Lett. 2004, 6, 3123.
(f) Srinivas, C. h.; Fang, X.; Wang, Q. Tetrahedron Lett.
2005, 46, 2331. (g) Hotha, S.; Kashyap, S. J. J. Org. Chem.
2006, 71, 364. Selected papers, supramolecular chemistry:
(h) Wu, P.; Feldman, A. K.; Nugent, A. K.; Hawker, C. J.;
Scheel, A.; Voit, B.; Pyun, J.; Fréchet, J. M. J.; Sharpless, K.
B.; Fokin, V. V. Angew. Chem. Int. Ed. 2004, 43, 3928.
(i) Collman, J. P.; Devaraj, N. K.; Chidsey, C. E. D.
Langmuir 2004, 20, 1051. (j) Bodine, K. D.; Gin, D. Y.;
Gin, M. S. J. Am. Chem. Soc. 2004, 126, 1638. (k) Dorner,
S.; Westermann, B. Chem. Commun. 2005, 2852.
(l) Billing, J. F.; Nilsson, U. J. J. Org. Chem. 2005, 70,
4847. Selected papers, polymer chemistry: (m) Laurent, B.
A.; Grayson, S. M. J. Am. Chem. Soc. 2006, 128, 4238.
(11) Jarosz, S.; Listkowski, A. Can. J. Chem. 2006, 492;
preferential silylation of the 6¢-OH over 6-OH is well
documented for free2 and partially protected sucrose4.
(12) Dondoni, A.; Marra, A. J. Org. Chem. 2006, 71, 7546.
(13) Bock, V. D.; Hiemstra, H.; van Maarseveen, J. H. Eur. J.
Org. Chem. 2006, 51.
1H NMR: d = 8.18 (s, 1 H, Htriazole), 7.10–7.40 (m, 30 H, HBn), 5.69
(d, J1,2 = 3.3 Hz, 1 H, H1), 3.40–5.05 (Hdisaccharide, CH2Ph).
13C NMR: d = 147.8 (Cq triazole), 138.9, 138.7, 138.0, 137.7,
137.64, 137.6 (6 Cq), 127.1 (CH-triazole), 107.0 (C2¢), 90.9 (C1),
84.2, 83.2, 83.1, 81.6, 81.4, 79. 6, 69.5 (C2, C3, C3¢, C4, C4¢, C5,
C5¢), 77.2, 75.4, 74.0, 73.5, 73.4, 72.9, 71.7, 71.6, 71.57, 60.3 (C1¢,
C6, C6¢, 6 OCH2Ph, OCH2-triazole).
MS: m/z = 1913 [M(C114H118N6O20) + Na]+.
Anal. Calcd for C114H118N6O20: C, 72.36; H, 6.26; N, 4.44. Found:
C, 72.18; H, 6.35; N, 4.32.
Intramolecular Cycloadducts 8
Yield: 88 mg (40%).
1H NMR: d = 8.22 (s, 0.55 H, 8a Htriazole), 7.72 (s, 0.45 H, 8b
Htriazole), 7.10–7.45 (m, 30 H, HBn), 5.62 (d, J1,2 = 3.64 Hz, 1 H, H1),
3.20–5.05 (Hdisaccharide, CH2Ph).
13C NMR: d = 141.2 (8b Cq triazole), 138.7, 138.4, 138.0, 137.55,
137.49, 137.1 (6 Cq), 134.8 (8b CH-triazole), 129.6 (8b Cq triazole),
125.4 (8a CH-triazole), 105.1 (C2¢), 91.48 and 91.44 (C1), 85.15
and 85.04, 83.7, 81.1 and 80.7, 79.99 and 79.82, 78.56 and 78.51,
77.2, 72.5 (C2, C3, C3¢, C4, C4¢, C5, C5¢), 75.39 and 75.36, 75.0,
73.8, 73.2, 72.3, 71.9, 70.7, 69.2, 69.0, 64.5 (C1¢, C6, C6¢,
6 OCH2Ph, OCH2-triazole).
MS: m/z = 968.4 [M(C57H59N3O10) + Na]+.
Anal. Calcd for C57H59N3O10: C, 72.36; H, 6.26; N, 4.44. Found: C,
72.30; H, 6.31; N, 4.29.
Acknowledgment
This work was financed by the Grant No PBZ-KBN-126/T09/07
from the Ministry of Science and Higher Education.
(14) Chandrasekhar, S.; Rao, Ch. L.; Nagesh, Ch.; Reddy, Ch. R.;
Sridhar, B. Tetrahedron Lett. 2007, 48, 5869.
(15) Although it is known that the Huisgen reaction (without
catalyst) usually provides a mixture of the 1,4- and 1,5-
triazoles reaction of sucrose synthon 6 with or without
catalyst gave the same product.
(16) The yields are reported for isolated compounds. In all
reactions we have observed significant amounts of tars
resulting (most likely) from the linear polymerization of the
monomer 6.
References
(1) Queneau, Y.; Jarosz, S.; Lewandowski, B.; Fitremann, J.
Adv. Carbohydr. Chem. Biochem. 2007, 61, 221.
(2) Review: Khan, R. Pure Appl. Chem. 1984, 56, 833; and
references therein.
(3) (a) Chan, J. Y. C.; Hough, L.; Richardson, A. C. J. Chem.
Soc., Perkin Trans. 1 1985, 1457. (b) de Raadt, A.; Stütz, A.
E. Tetrahedron Lett. 1992, 33, 189. (c) Garndnig, G.;
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