Synlett 2002(6): 0867-0870
DOI: 10.1055/s-2002-31926
LETTER
© Georg Thieme Verlag Stuttgart · New York

Solid-Phase Synthesis of Aryl O-Glycoside Using Aqueous Base and Phase-Transfer Catalyst

Tatsuya Zenkoha, Hiroshi Tanakac, Hiroyuki Setoib, Takashi Takahashi*c
a Exploratory Research Laboratories, Fujisawa Pharmaceutical Co. Ltd., 5-2-3 Tokodai, Tsukuba, Ibaraki 300-2698, Japan
Fax: +81(298)478610; e-Mail: tatsuya_zenkoh@po.fujisawa.co.jp;
b Medicinal Chemistry Research Laboratories, Fujisawa Pharmaceutical Co. Ltd., 2-1-6 Kashima, Yodogawa-ku, Osaka 532-8514, Japan
c Department of Applied Chemistry, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8552, Japan
Fax: +81(3)57342884; e-Mail: thiroshi@o.cc.titech.ac.jp;
Further Information

Publication History

Received 5 March 2002
Publication Date:
07 February 2007 (online)

Abstract

We describe an efficient solid-phase synthesis of aryl O-glycosides using aqueous base and phase-transfer catalyst. This methodology can provide aryl O-glycosides selectively in excellent yield and purity without the production of C-glycoside. Application of this methodology to the synthesis of Phlorizin type aryl O-glycosides is reported.

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ArgoGelΤ Μ (Wang chloride resin) was purchased from Argonaut Technologies, San Carlos, CA.

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Column: Mightysil RP-18 GP (ODS) 3 µm, 4.6 mmI. D. × 50 mm; mobile phase: 20 mM NH4OAc: MeOH = 70: 30 (0 min) Æ 10:90 (4 - 8 min); UV: 254 nm.

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General Procedure for Glycosylation of Phenol Exemplified with the Synthesis of m -10: The resin m -6 (4 × 30 mg, 0.17 mmol/g) was loaded into IRORIΤ Μ MicroKans. To a solution of Cs2CO3 in THF-MeOH (1:1, 4 mL) was added the MicroKans at ambient temperature. After being shaked for 17 h at the same temperature, the reaction mixture was drained to isolate the Kans. The Kans were sequentially washed with DMF (4 × 5 mL), THF-water (2:1, 4 × 5 mL), 5% HOAc-THF (4 × 5 mL), THF (4 × 5 mL), MeOH (4 × 5 mL), and dichloromethane (DCM) (4 × 5 mL) and dried in vacuo to give immobilized phenol m -7 in four Kans. Three MicroKans among them were exposed to a solution of glucosyl bromide 8a (463 mg) in 1,2-dichloroethane (4.2 mL). To the mixture were successively added 5% NaOH aq (2.1 mL), benzyl tri-n-butylammonium chloride (21.9 mg). After being shaked at ambient temperature for 15 h, the mixture was drained. Remaining three Kans were washed sequentially with DCM (5 mL), DMF (4 × 5 mL), THF-MeOH (1:1, 2 × 5 mL), 5% HOAc-THF (2 × 5 mL), THF (4 × 5 mL), MeOH (4 × 5 mL), and DCM (4 × 5 mL) and dried to give glycoside m -9. The resin in the three MicroKans was cleaved with 10% TFA-DCM (5 mL) for 30 min. The resulting solution was diluted with DCM (5 mL) and toluene (2 mL). The MicroKans were removal from the solution by means of tweezers. The acidic solution was concentrated to afford m -10 (9.8 mg, 0.014 mmol, 93%). Spectrum data of m -10: 1H NMR (300 MHz, CDCl3): δ = 8.03 (2 H, dd, J = 1.2, 8.4 Hz), 7.99-7.90 (4 H, m), 7.86 (2 H, dd, J = 1.5, 8.4 Hz), 7.58-7.25 (13 H, m), 7.04-6.97 (1 H, m), 6.60-6.47 (3 H, m), 5.98 (1 H, dd, J = 9.4, 9.6 Hz), 5.79 (1 H, dd, J = 7.8, 9.4 Hz), 5.70 (1 H, dd, J = 9.4, 9.6 Hz), 5.37(1 H, d, J = 7.8 Hz), 4.68 (1 H, dd, J = 3.3, 12.3 Hz), 4.53 (1 H, dd, J = 6.3, 12.3Hz), 4.37-4.28 (1 H, m); MS (ESI): 706 [M + NH4 +].

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Spectrum data, p -10: 1H NMR (300 MHz, CDCl3): δ = 8.05-7.82 (8 H, m), 7.58-7.24 (13 H, m), 6.89 (2 H, d, J = 9.0 Hz), 6.61 (2 H, d, J = 9.0 Hz), 5.97 (1 H, dd, J = 9.6, 9.9 Hz), 5.76 (1 H, dd, J = 8.1, 9.9 Hz), 5.70 (1 H, dd, J = 9.6, 9.9 Hz), 5.26 (1 H, d, J = 8.1 Hz), 4.66 (1 H, dd, J = 3.0, 12.3 Hz), 4.53 (1 H, dd, J = 6.3, 12.3 Hz), 4.30-4.23 (1 H, m); MS (ESI): 706 [M + NH4 +].

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Spectrum data, 18a: 1H NMR (300 MHz, CDCl3): δ = 12.99 (1 H, s), 7.99 (2 H, d, J = 8.0 Hz), 7.96-7.89 (4 H, m), 7.84 (2 H, d, J = 8.0 Hz), 7.60-7.24 (12 H, m), 7.10 (1 H, dd, J = 8.1, 8.4 Hz), 6.61 (1 H, d, J = 8.4 Hz), 6.56 (1 H, d, J = 8.1 Hz), 6.03 (1 H, dd, J = 9.6, 10.0 Hz), 5.92 (1 H, dd, J = 7.5, 9.6 Hz), 5.74 (1 H, dd, J = 9.6, 10.0 Hz), 5.63 (1 H, d, J = 7.5 Hz), 4.68 (1 H, dd, J = 2.7, 13.2 Hz), 4.52 (1 H, dd, J = 7.8, 13.2 Hz), 4.42-4.33 (1 H, m), 2.61 (3 H, s); MS (ESI): 748 [M + NH4 +]. 18b: 1H NMR (300 MHz, CDCl3): δ = 13.00 (1 H, s), 8.09 (2 H, dd, J = 1.5, 8.4 Hz), 8.03 (2 H, dd, J = 1.5, 8.4 Hz), 7.91 (2 H, dd, J = 1.5, 8.7 Hz), 7.81 (2 H, dd, J = 1.5, 8.7 Hz), 7.68-7.23 (12 H, m), 7.10 (1 H, dd, J = 7.5, 8.4 Hz), 6.63 (1 H, d, J = 7.5 Hz), 6.60 (1 H, d, J = 8.4 Hz), 6.17 (1 H, dd, J = 8.1, 10.2 Hz), 6.07 (1 H, d, J = 3.3 Hz), 5.71 (1 H, dd, J = 3.3, 10.2 Hz), 5.62 (1 H, d, J = 8.1 Hz), 4.67-4.50 (3 H, m), 2.65 (3 H, s); MS (ESI): 748 [M + NH4 +]. 18c: 1H NMR (300 MHz, CDCl3): δ = 12.97 (1 H, s), 8.03 (2 H, d, J = 6.9 Hz), 7.99-7.88 (4 H, m), 7.61-7.30 (10 H, m), 6.68 (2 H, dd, J = 2.0, 8.4 Hz), 5.92 (1 H, dd, J = 7.5, 7.8 Hz), 5.77 (1 H, dd, J = 5.7, 7.8 Hz), 5.64 (1 H, d, J = 5.7 Hz), 5.49-5.40 (1 H, m), 4.53 (1 H, dd, J = 3.5, 13.2 Hz), 3.89 (1 H, dd, J = 8.0, 13.2 Hz), 2.62 (3 H, s); MS (ESI): 614 [M + NH4 +]. 18d: 1H NMR (300 MHz, CDCl3): δ = 12.97 (1 H, s), 8.06 (2 H, dd, J = 1.5, 8.4 Hz), 7.98 (2 H, dd, J = 1.5, 8.7 Hz), 7.91 (2 H, dd, J = 1.2, 8.4 Hz), 7.65-7.25 (10 H, m), 6.69 (1 H, d, J = 8.4 Hz), 6.67 (1 H, d, J = 8.4 Hz), 6.09 (1 H, dd, J = 6.6, 9.0 Hz), 5.81-5.75 (1 H, m), 5.71 (1 H, dd, J = 3.3, 9.0 Hz), 5.58 (1 H, d, J = 6.6 Hz), 4.43 (1 H, dd, J = 3.9, 13.2 Hz), 4.08 (1 H, dd, J = 2.0, 13.2 Hz), 2.66 (3 H, s); MS (ESI): 614 [M + NH4 +].