Synlett 2017; 28(15): 2024-2029
DOI: 10.1055/s-0036-1588864
letter
© Georg Thieme Verlag Stuttgart · New York

Ferric Chloride: An Eco-friendly Catalyst for the Stereoselective Synthesis of 2-Deoxy Aryl-O-Rhamnosides

Saifeng Qiu
School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, P.R. of China   Email: Jbzhang@chem.ecnu.edu.cn
,
Guosheng Sun
School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, P.R. of China   Email: Jbzhang@chem.ecnu.edu.cn
,
Zekun Ding
School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, P.R. of China   Email: Jbzhang@chem.ecnu.edu.cn
,
Heshan Chen
School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, P.R. of China   Email: Jbzhang@chem.ecnu.edu.cn
,
Jianbo Zhang*
School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, P.R. of China   Email: Jbzhang@chem.ecnu.edu.cn
› Author Affiliations
Further Information

Publication History

Received: 15 March 2017

Accepted after revision: 15 May 2017

Publication Date:
29 June 2017 (online)


Abstract

A facile and direct O-glycosylation method for the stereoselective synthesis of 2,6-dideoxy α-O-aryl-glycosides has been described using an eco-friendly catalyst, ferric chloride (FeCl3). The approach can be applied to a wide range of differently substituted phenols including not only mono-substituted ones bearing electron-donating and electron-withdrawing groups but also disubstituted ones. Ultimately, 2,6-dideoxy aryl-O-glycosides were obtained rapidly (<30 min) in good to excellent yields (52–88%) with sole α-selectivity.

Supporting Information

 
  • References and Notes

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  • 9 Yang G. Wang Q. Luo X. Zhang J. Tang J. Glycoconj. J. 2012; 29: 453
  • 10 Lam SN. Gervay-Hague J. Org. Lett. 2003; 5: 4219
  • 13 Zhou J. Chen H. Shan J. Li J. Yang G. Chen X. Xin K. Zhang J. Tang J. J. Carbohydr. Chem. 2014; 33: 313
  • 14 Qiu S. Zhang W. Sun G. Wang Z. Zhang J. ChemistrySelect 2016; 1: 4840
  • 16 Adhikari S. Baryal KN. Zhu D. Li X. Zhu J. ACS Catalysis 2013; 3: 57
  • 17 Piersanti G. Retini M. Espartero JL. Madrona A. Zappia G. Tetrahedron Lett. 2011; 52: 4938
  • 19 See Supporting Information.
  • 22 General Procedure To a solution of the glycosyl donor 1 (41.1 mg, 0.15 mmol) in anhydrous MeCN (4 mL) was added a glycosyl acceptor phenol (0.1 mmol). After stirring for 5 min, 32.4 µL of anhydrous FeCl3 solution (0.002 mmol of FeCl3 in MeCN) were added at 0 °C. After completion (monitored by TLC), the reaction mixture was quenched with saturated aqueous NaHCO3 solution (5 mL) and extracted with CH2Cl2 (5 mL × 2). The combined organic layers were washed with brine (5 mL), dried over anhydrous Na2SO4, filtered, and concentrated under vacuum. The crude product was purified by column chromatography with petroleum ether/ethyl acetate as an eluent to obtain the corresponding glycosides.
  • 23 Selected Spectral Data p-(tert-Butyl)phenyl 2-deoxy-3,4-di-O-acetyl rhamnopyranoside (3a) 1H NMR (500 MHz, CDCl3): δ = 7.30 (d, J = 8.7 Hz, 2 H), 7.00 (d, J = 8.7 Hz, 2 H), 5.57 (d, J = 2.1 Hz, 1 H), 5.48 (ddd, J = 11.5, 9.6, 5.4 Hz, 1 H), 4.82 (t, J = 9.6 Hz, 1 H), 3.98 (dq, J = 12.4, 6.2 Hz, 1 H), 2.42 (dd, J = 12.7, 4.9 Hz, 1 H), 2.06 (s, 3 H), 2.04 (s, 3 H), 1.94 (td, J = 12.8, 3.4 Hz, 1 H), 1.30 (s, 9 H), 1.15 (d, J = 6.2 Hz, 3 H). 13C NMR (125 MHz, CDCl3): δ = 170.50, 170.40, 154.42, 144.99, 126.40, 115.87, 95.38, 74.84, 69.06, 66.49, 35.58, 34.29, 31.63, 21.19, 20.99, 17.74. HRMS (ESI): m/z [M + Na]+ calcd for C20H28O6Na: 387.1778; found: 387.1775. p-(2′-O-acetyl)-ethylphenyl 2-deoxy-3,4-di-O-acetyl rhamnopyranoside (3d) 1H NMR (500 MHz, CDCl3): δ = 7.13 (d, J = 8.3 Hz, 2 H), 7.00 (d, J = 8.3 Hz, 2 H), 5.57 (d, J = 2.0 Hz, 1 H), 5.47 (ddd, J = 11.6, 9.6, 5.4 Hz, 1 H), 4.82 (t, J = 9.6 Hz, 1 H), 4.24 (t, J = 7.1 Hz, 2 H), 3.95 (dq, J = 12.4, 6.2 Hz, 1 H), 2.88 (t, J = 7.0 Hz, 2 H), 2.43 (dd, J = 12.9, 5.3 Hz, 1 H), 2.05 (s, 3 H), 2.04 (s, 3 H), 2.04 (s, 3 H), 1.98–1.90 (m, 1 H), 1.14 (d, J = 6.2 Hz, 3 H). 13C NMR (125 MHz, CDCl3): δ = 171.19, 170.50, 170.37, 155.32, 131.57, 130.02, 116.47, 95.28, 74.75, 68.99, 66.56, 65.20, 35.50, 34.39, 21.18, 21.13, 20.98, 17.72. HRMS (ESI): m/z [M + Na]+ calcd for C20H26O8Na: 417.1520; found: 417.1529. 2,4-Dimethylphenyl 2-deoxy-3,4-di-O-acetyl rhamnopyranoside (3h) 1H NMR (500 MHz, CDCl3): δ = 6.98 (d, J = 8.5 Hz, 2 H), 6.93 (d, J = 8.3 Hz, 1 H), 5.55 (d, J = 2.6 Hz, 1 H), 5.47 (ddd, J = 11.5, 9.6, 5.3 Hz, 1 H), 4.83 (t, J = 9.7 Hz, 1 H), 3.96 (dq, J = 12.5, 6.2 Hz, 1 H), 2.46 (ddd, J = 12.8, 5.3, 0.9 Hz, 1 H), 2.26 (s, 3 H), 2.24 (s, 3 H), 2.06 (s, 3 H), 2.04 (s, 3 H), 1.96 (ddd, J = 13.5, 11.0, 3.5 Hz, 1 H), 1.15 (d, J = 6.3 Hz, 3 H). 13C NMR (125 MHz, CDCl3): δ = 170.48, 170.40, 152.62, 131.72, 131.32, 130.80, 127.22, 114.02, 95.35, 74.82, 69.16, 66.55, 35.76, 21.20, 21.00, 20.64, 17.74, 16.34. HRMS (ESI): m/z [M + Na]+ calcd for C18H24O6Na: 359.1465; found: 359.1467. p-Fluorophenyl 2-deoxy-3,4-di-O-acetyl rhamnopyranoside (3j) 1H NMR (500 MHz, CDCl3): δ = 7.08–6.51 (m, 4 H), 5.51 (d, J = 2.9 Hz, 1 H), 5.45 (ddd, J = 11.5, 9.7, 5.4 Hz, 1 H), 4.82 (t, J = 9.7 Hz, 1 H), 3.94 (dq, J = 12.5, 6.2 Hz, 1 H), 2.43 (dd, J = 13.0, 5.2 Hz, 1 H), 2.05 (s, 3 H), 2.04 (s, 3 H), 1.97–1.91 (m, 1 H), 1.14 (d, J = 6.2 Hz, 3 H). 13C NMR (125 MHz, CDCl3): δ = 170.47, 170.31, 158.19 (d, J = 240.0 Hz), 152.61, 117.65 (d, J = 8.0 Hz), 116.01 (d, J = 23.1 Hz), 95.76, 74.63, 68.89, 66.61, 35.43, 21.15, 20.95, 17.68. HRMS (ESI): m/z [M + Na]+ calcd for C16H19O6FNa: 349.1058; found: 349.1053. 3,5-Dibromophenyl 2-deoxy-3,4-di-O-acetyl rhamnopyranoside (3o) 1H NMR (500 MHz, CDCl3): δ = 7.32 (t, J = 1.5 Hz, 1 H), 7.19 (d, J = 1.6 Hz, 2 H), 5.56 (d, J = 2.7 Hz, 1 H), 5.39 (ddd, J = 11.5, 9.6, 5.4 Hz, 1 H), 4.83 (t, J = 9.7 Hz, 1 H), 3.87 (dq, J = 10.0, 6.2 Hz, 1 H), 2.43 (ddd, J = 13.1, 5.3, 1.0 Hz, 1 H), 2.06 (s, 3 H), 2.04 (s, 3 H), 1.94 (ddd, J = 13.2, 11.7, 3.6 Hz, 1 H), 1.16 (d, J = 6.2 Hz, 3 H). 13C NMR (125 MHz, CDCl3): δ = 170.42, 170.27, 157.51, 128.05, 123.22, 118.71, 95.53, 74.30, 68.61, 67.11, 35.16, 21.13, 20.94, 17.71. HRMS (ESI): m/z [M + Na]+ calcd for C16H18O6Br2Na: 486.9362; found: 486.9365.