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J. Ning et al. / Tetrahedron Letters 43 (2002) 5545–5549
nonasaccharide 27, respectively, deprotection of which
gave the corresponding compounds 1 and 3. Utilizing
the same procedure used for the preparation of 18, the
heptasaccharide glycosyl donor 20 was obtained from
19. Similarly, the 6-O-acetyl hexasaccharide 22 and
heptasaccharide 25 were obtained from 21 and 24.
Selective 6-O-deacetylation of 22 and 25 gave the hexa-
saccharide glycosyl acceptor 23 and heptasaccharide
glycosyl acceptor 26, respectively. Coupling of 18 with
23 gave the dodecasaccharide 28, while condensation of
20 with 26 afforded the tetradecasaccharide 29. Com-
pounds 4 and 5 were obtained by deprotection of 28
and 29, respectively.
164, 297–306; (d) Fugedi, P.; Garegg, P. J.; Kvarnstrom,
I.; Pilotti, A. J. Carbohydr. Chem. 1989, 8, 47–58; (e)
Fugedi, P.; Garegg, P. J.; Kvarnstrom, I.; Svansson, L. J.
Carbohydr. Chem. 1988, 7, 389–402; (f) Hong, N.; Ogawa,
T. Tetrahedron Lett. 1990, 31, 3179–3182; (g) Lorentzen,
P. J.; Helpap, B.; Lockhoff, O. Angew. Chem., Int. Ed.
Engl. 1991, 30, 1681–1684; (h) Cheong, J.-J.; Birberg, W.;
Fugedi, P.; Pilloti, A.; Garegg, P. J.; Hong, N.; Ogawa, T.;
Hahn, M. G. Plant Cell. 1991, 127–131; (i) Hong, N.;
Nakahara, Y.; Ogawa, T. Proc. Jpn. Acad. 1993, 55,
698–704; (j) Yamada, H.; Harada, T.; Takahashi, T. J.
Am. Chem. Soc. 1994, 116, 7919–7920; (k) Nicolaou, K.
C.; Winssinger, N.; Pastor, J.; Derosse, F. J. Am. Chem.
Soc. 1997, 119, 449–450; (l) Plante, O. J.; Palmacci, E. R.;
Seeberger, P. H. Science 2001, 291, 1523–1525.
In all of the syntheses, the reactions were carried out
smoothly in high yields and in large scale. Several
intermediates were not separated, but were used directly
in further reactions thereby simplifying the procedures
substantially. Preparation of the hexasaccharide 2 on a
100 g scale has been accomplished in our laboratory.
7. Ning, J.; Kong, F. PCT WO 01/23397 A1.
8. (a) Scott, D. S.; Piskorz, J.; Radlein, D. Energy, Biomass,
Waters 1993, 16, 797–809; (b) Zhuang, X. L. Ph.D. Disser-
tation, Chinese Academy of Sciences, 2001; (c) Scott, D.
S.; Radlein, D.; Piskorz, J.; Majerski, P. In Biomass Ther-
mal Processing; Hogan, E.; Roberts, J.; Grassi, G.; Bridge-
water, A. V., Eds. Potential of fast pyrolysis for the
production of chemicals; Chaelon Press: London, 1992;
pp. 171–178; (d) Zhuang, H. X.; Zhuang, X. L. Chinese
Patent, Application No: 00107956.5, 2000; (e) Moens, L.
US Patent, No: 5371212, 1994; (f) Gander, M.; Rapp, K.
M.; Schiweck, H. US Patent, No: 5023330, 1991.
In summary, a general strategy for the preparation of
3,6-branched gluco-oligosaccharides has been devel-
oped. The strategy presented here also provides a route
to the synthesis of b-(16) branched b-(13)-linked
gluco-oligosaccharides which exist in many antitumor
polysaccharides such as schizophyllan, sceroglucan and
lentinan. The construction and bioassays of b-(16)
branched b-(13)-linked gluco-oligosaccharides are in
progress.
9. All new compounds gave satisfactory elemental analysis
results. Selected physical data for some key compounds
are as follows, for 12: mp 121–123°C; [h]D +34 (c 2.5,
CHCl3). 1H NMR (400 MHz, CDCl3): l 8.11–7.28 (m,
20H, 4 PhH), 5.94 (dd, 1H, J=9.7 Hz, H-3%), 5.72 (dd, 1H,
J=9.7 Hz, H-4%), 5.54 (dd, 1H, J=7.9, 9.7 Hz, H-2%), 5.53
(d, 1H, J=3.6 Hz, H-1), 5.03 (d, 1H, J=7.9 Hz, H-1%),
4.84 (dd, 1H, J=3.6, 11.9 Hz, H-6a%), 4.42 (dd, 1H,
J=4.3, 11.9 Hz, H-6b%), 4.41 (d, 1H, J=2.6, H-3), 4.24–
4.23 (m, 2H, H-2, 5%), 4.16 (dd, 1H, J=2.6, 8.8 Hz, H-4),
4.02 (m, 1H, H-5), 3.83 (dd, 1H, J=3.2, 11.4 Hz, H-6a),
3.67 (dd, 1H, J=6.0, 11.4 Hz, H-6b), 1.44, 1.09 (2s,
C(CH3)2). Anal. calcd for C43H42O15: C, 64.66; H, 5.30.
Found: C, 64.79; H, 5.25. For 13: [h]D+25.3 (c 1.0,
CHCl3); 1H NMR (400 MHz, CDCl3): l 8.06–7.28 (m,
40H, 8 PhH), 5.88 (dd, 1H, J=9.7 Hz, H-3), 5.87 (dd, 1H,
J=9.7 Hz, H-3), 5.69 (dd, 1H, J=9.7 Hz, H-4), 5.64 (dd,
1H, J=9.7 Hz, H-4), 5.53 (dd, 1H, J=7.9, 9.7 Hz, H-2),
5.43 (dd, 1H, J=7.9, 9.7 Hz, H-2), 5.41 (d, 1H, J=3.5 Hz,
H-1), 4.96 (d, 1H, J=7.9 Hz, H-1), 4.93 (d, 1H, J=7.9 Hz,
H-1), 4.68 (dd, 1H, J=3.4, 12.3 Hz, H-6), 4.48 (dd, 1H,
J=4.9, 12.2 Hz, H-6), 4.67 (dd, 1H, J=3.4, 12.2 Hz, H-6),
4.35 (dd, 1H, J=4.9, 12.2 Hz, H-6), 4.34–3.65 (m, 8H),
1.26, 1.03 (2s, 6H, (CCH3)2). Anal. calcd for C77H68O24: C,
67.15; H, 4.98. Found: C, 67.29; H, 5.02. For 14: [h]D
Acknowledgements
This work was supported by the Beijing Natural Sci-
ence Foundation (6021004) and the National Natural
Science Foundation of China (Project 59973026 and
29905004), and by The Ministry of Science and
Technology.
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1
+23.3 (c 1.0, CHCl3); H NMR (400 MHz, CDCl3) l 8.33
(s, 1H, CNHCCl3), 8.07–7.19 (m, 40H, 8 PhH), 6.19 (d,
1H, J=3.6), 5.91 (dd, 1H, J=9.6 Hz), 5.85 (dd, 1H,
J=9.6 Hz), 5.62 (dd, 1H, J=9.6 Hz), 5.61 (dd, 1H, J=9.6
Hz), 5.46 (dd, 1H, J=7.9, 9.6 Hz), 5.42 (dd, 1H, J=7.9,
9.6 Hz), 4.97 (d, 1H, J=7.9 Hz), 4.96 (d, 1H, J=7.9 Hz),
4.85 (dd, 1H, J=9.5 Hz), 4.67–4.59 (m, 3H), 4.50–4.37 (m,
2H), 4.19–4.02 (m, 4H), 3.91 (dd, 1H), 3.69 (dd, 1H), 1.94,
1.78 (2s, 6H, 2 CH3CO). Anal. calcd for C80H68Cl3NO26:
C, 61.37; H, 4.38. Found: C, 61.53; H, 4.41. For 15:
1
[h]D+18.6 (c 1.1, CHCl3); H NMR (400 MHz, CDCl3) l