Synlett 2002(6): 0911-0914
DOI: 10.1055/s-2002-31933
LETTER
© Georg Thieme Verlag Stuttgart · New York

Solid-Phase Synthesis of a Phytoalexin Elicitor-Active Tetraglucosyl Glucitol

Takashi Takahashi*, Akihiro Okano, Toru Amaya, Hiroshi Tanaka, Takayuki Doi
Department of Applied Chemistry, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8552, Japan
Fax: +81(3)57342884; e-Mail: ttakashi@o.cc.titech.ac.jp;
Further Information

Publication History

Received 6 April 2002
Publication Date:
07 February 2007 (online)

Abstract

A solid-phase synthesis of pentasaccharide 1 that has phytoalexin elicitor activity for rice is described. Efficient block-type synthesis by β-selective glycosylation with thioglycosides A 3 and B 2 at the 3-position of the polymer-supported glycosyl acceptor has been demonstrated.

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Compound 7 was prepared from 2 by deprotection of TBS (see ref. [3b] ) and glycosidation of the corresponding 3,6-hydroxy free phenyl thioglucoside with excess benzyl alcohol (NIS-TfOH, CH2Cl2, MS 4 Å, 0 °C, 52%).

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Spectral data of B 2 : 1H NMR (400 MHz, CDCl3): δ = -0.22 (s, 3 H), -0.11 (s, 3 H), 0.72 (s, 9 H), 1.08 (dd, 3 H, J = 7.2, 7.2 Hz), 2.39 (s, 3 H), 2.49 (dq, 1 H, J = 7.2, 12.5 Hz), 2.59 (dq, 1 H, J = 7.2, 12.5 Hz), 3.41 (dd, 1 H, J = 8.7, 9.7 Hz), 3.45-3.57 (m, 2 H), 3.63 (dd, 1 H, J = 5.3, 11.1 Hz), 3.72-3.88 (m, 5 H), 4.12 (brd, 1 H, J = 10.6 Hz), 4.37 (d, 1 H, J = 10.2 Hz), 4.45 (d, 1 H, J = 11.6 Hz), 4.53-4.59 (m, 4 H), 4.64 (d, 1 H, J = 12.1 Hz), 4.65 (d, 1 H, J = 11.1 Hz), 4.71 (d, 1 H, J = 11.1 Hz), 4.80 (d, 1 H, J = 11.1 Hz), 5.13 (dd, 1 H, J = 9.2, 9.7 Hz), 5.31 (dd, 1 H, J = 8.2, 8.2 Hz), 7.09-7.39 (m, 22 H), 7.42 (dd, 2 H, J = 7.3, 7.7 Hz), 7.55 (t, 1 H, J = 7.3 Hz), 7.89 (d, 2 H, J = 7.7 Hz), 8.01 (d, 2 H, J = 7.3 Hz); 13C NMR (99.6 MHz, CDCl3): δ = -4.4, -4.1, 14.8, 17.7, 21.6, 23.4, 25.6, 67.9, 68.8, 73.0, 73.6, 74.6, 75.0, 75.3, 77.9, 78.5, 79.1, 82.9, 83.1, 101.1, 127.2, 127.4, 127.6, 127.8, 128.0, 128.2 × 2, 128.4, 129.1, 129.9, 130.4, 132.9, 137.9, 138.0, 138.2, 143.6, 165.0, 165.3; MS (FAB): 1105 [M + Na]+.

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Spectral data of 21: [α]D 27 +22.6 (c 0.400 in CHCl3); 1H NMR (400 MHz, CDCl3): δ = 3.18-3.78 (m, 27 H), 3.85 (dd, J = 9.2, 9.2 Hz, 1 H), 3.96 (d, J = 9.7 Hz, 1 H), 4.05 (brd, J = 7.25 Hz, 1 H), 4.25 (d, J = 12.1 Hz, 1 H), 4.30 (d, J = 12.1 Hz, 1 H), 4.38-4.81 (m, 18 H), 4.86 (d, J = 12.1 Hz, 1 H), 4.89 (d, J = 11.6 Hz, 1 H), 5.00 (d, J = 11.1 Hz, 1 H), 5.07 (d, J = 11.1 Hz, 1 H), 5.15 (d, J = 11.1 Hz, 1 H), 7.15-7.35 (m, 50 H); 13C NMR (99.6 MHz, CDCl3): δ = 61.8, 68.2, 68.3, 68.9, 71.5, 73.1, 73.3, 73.4, 73.7, 74.4, 74.6, 74.7, 74.8, 74.9, 75.0, 75.2, 75.3, 75.4, 76.0, 77.6, 84.4, 84.6, 85.5, 86.6, 87.9, 101.4, 103.4, 103.6, 104.9, 105.5, 127.5, 127.6, 127.7, 127.8, 127.9 × 2, 128.0, 128.1, 128.2, 128.3, 128.5, 128.8, 130.1, 133.5, 137.0, 137.8, 137.9, 138.1 × 2, 138.2, 138.3, 138.4 × 2, 138.5, 138.8, 138.9; MS (ESI-TOF): 1752 [M + Na]+.