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2940
R. Johnsson, U. Ellervik
LETTER
Duchet, D.; Milat, M.-L.; Sinaÿ, P. J. Am. Chem. Soc. 1977,
99, 6762. (c) Yoshizaki, H.; Fukuda, N.; Sato, K.; Oikawa,
M.; Fukase, K.; Suda, Y.; Kusumoto, S. Angew. Chem. Int.
Ed. 2001, 40, 1475.
Table 3 Anomeric Deacetylation of Peracetylated Carbohydrates
by Polymer-Bound Benzylamine16
O
O
OAc
OH
(2) (a) Caputo, R.; Kunz, H.; Mastroianni, D.; Palumbo, G.;
Pedatella, S.; Solla, F. Eur. J. Org. Chem. 1999, 3147.
(b) Kobayashi, S.; Yoneda, A.; Fukuhara, T.; Hara, S.
Tetrahedron 2004, 60, 1287.
Entry Starting material
Conversion a/b
(%)a
(3) (a) Schmidt, R. R. Angew. Chem., Int. Ed. Engl. 1986, 25,
212. (b) Schmidt, R. R.; Klotz, W. Synlett 1991, 168.
(4) Excoffier, G.; Gagnaire, D.; Utille, J.-P. Carbohydr. Res.
1975, 39, 368.
(5) Watanbe, K.; Itoh, K.; Araki, Y.; Ishido, Y. Carbohydr. Res.
1986, 154, 165.
1
2
96
96
5:3
3:1
O
AcO
AcO
OAc
OAc
OAc
OAc
O
AcO
AcO
(6) (a) Nudelman, A.; Herzig, J.; Gottlieb, H. E.; Keinan, E.;
Sterling, J. Carbohydr. Res. 1987, 162, 145. (b) Herzig, J.;
Nudelman, A.; Gottlieb, H. E. Carbohydr. Res. 1988, 177,
21.
(7) Sambaiah, T.; Fanwick, P. E.; Cushman, M. Synthesis 2001,
1450.
(8) Helferich, B.; Portz, W. Chem. Ber. 1953, 86, 604.
(9) Itoh, K.; Takamura, H.; Watanbe, K.; Araki, Y.; Ishido, Y.
Carbohydr. Res. 1986, 156, 241.
OAc
3
4
96
90
2:1
5:2
OAc
O
AcO
AcO
AcO
OAc
OAc
OAc
O
OAc
AcO
AcO
AcO
(10) Blazejewski, J.-C.; Dorme, R.; Wakselman, C. Synthesis
OAc
OAc
OAc
O
1985, 1121.
5
6
95
88
1:0
4:3
(11) Mikamo, M. Carbohydr. Res. 1989, 191, 150.
(12) Rowell, R. M.; Feather, M. S. Carbohydr. Res. 1967, 4, 486.
(13) Schneider, G.; Weisz-Vincze, I.; Vass, A.; Kovács, K.
Tetrahedron Lett. 1972, 32, 3349.
(14) Herzig, J.; Nudelman, A. Carbohydr. Res. 1986, 153, 162.
(15) Representative Experimental Procedure.
1,2,3,4,6-Penta-O-acetyl-b-D-glucopyranose (11 mg, 0.028
mmol) and aminomethylated polystyrene resin (60 mg, 0.90
mmol/g) were mixed in THF (1 mL) in a sealed tube. Then,
Et3N (0.011 mL, 0.0078 mmol) was added and the mixture
was heated to 75 °C for 18 h. The mixture was filtered with
CH2Cl2 and concentrated from CHCl3. NMR showed 96%
product and 4% starting material.
(16) All compounds are commercially available except for
(a) 2,3,4-tri-O-acetyl-D-xylopyranose: Utille, J.-P.;
Gagnaire, D. Carbohydr. Res. 1982, 106, 43. (b) 2,3,4,6-
Tetra-O-acetyl-D-galactopyranose: Sim, M. M.; Kondo, H.;
Wong, C.-H. J. Am. Chem. Soc. 1993, 115, 2260. (c) 2,3,6-
Tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-b-D-galacto-
pyranosyl)-D-glucopyranose: Ross, A. J.; Ivanova, I. A.;
Ferguson, M. A. J.; Nikolaev, A. V. J. Chem. Soc., Perkin
Trans. 1 2001, 72.
(17) 1,2,3,4,6-Penta-O-acetyl-b-D-glucopyranose (53 mg, 0.14
mmol) and aminomethylated polystyrene resin (288 mg,
0.90 mmol/g) were mixed in THF (5 mL) in a sealed tube.
Then, Et3N (0.05 mL, 0.0004 mmol) was added and the
mixture was heated to 75 °C for 18 h. The mixture was
filtered with CH2Cl2 and concentrated. The crude product
was dissolved in CH2Cl2 (1 mL) and cooled to –10 °C under
argon. Thereafter, Cl3CCN (0.136 mL, 1.36 mmol) and DBU
(0.005 mL, 0.033 mmol) were added and the reaction was
allowed to reach r.t. and then stirred for 3 h. To this mixture
DBU (0.005 mL, 0.033 mmol) was added and the
composition was stirred for another hour and then
concentrated and chromatographed (SiO2, 1:1 heptane–
EtOAc) to give 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl
trichloroacetimidate (57 mg, 85%). The product was in
agreement with published data.
OAc
AcO
OAc
OAc
OAc
O
O
O
OAc
AcO
OAc
OAc
a The reactions were run for 18 h (entries 1–5) or 44 h (entry 6), fil-
tered and concentrated. The conversion was estimated by NMR.
To verify the usefulness of our method peracetylated glu-
cose was deprotected and subsequently converted to the
trichloroacetimidate by reaction with trichloroacetonitrile
and DBU (Scheme 1).17 2,3,4,6-Tetra-O-acetyl-D-glu-
copyranosyl trichloroacetimidate was isolated in 85%
yield, which is comparable to yields reported for synthesis
from the hemiacetal.18
OAc
O
OAc
O
NH
a, b
AcO
AcO
AcO
AcO
OAc
O
85%
CCl3
OAc
OAc
Scheme 1 Synthesis of 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl
trichloroacetimidate. Reagents and conditions: (a) aminomethylated
polystyrene, Et3N, THF; (b) Cl3CCN, DBU, CH2Cl2.
To summarize, we have introduced a new method using
polymer-bound amines for highly effective and selective
1-O-deacetylation of peracetylated carbohydrates without
the need for subsequent purification.
Acknowledgment
This work was supported by the Swedish Research Council and the
Crafoord Foundation.
(18) Cook, B. N.; Bhakta, S.; Biegel, T.; Bowman, K. G.;
Armstrong, J. I.; Hemmerich, S.; Bertozzi, C. R. J. Am.
Chem. Soc. 2000, 122, 8612.
References
(1) (a) Schmidt, R. R.; Jung, K.-H. Preparative Carbohydrate
Chemistry; Hanessian, S., Ed.; Marcel Dekker: New York,
1996, 283. (b) Pougny, J.-R.; Jacquinet, J.-C.; Nassr, M.;
Synlett 2005, No. 19, 2939–2940 © Thieme Stuttgart · New York