Synthesis of Fully Protected N‐Arylglycosylamines and Factors Affecting the Configuration of C₁‐Substituents of N‐Arylglycosylamines

Abstract

An efficient method was reported for preparation of N‐arylglycosylamines in aqueous THF under reflux in good yields. The factors affecting the configuration of C₁‐substituents of N‐aryglycosylamines was investigated, that is, the influence of solvents, substituents of aromatic amines, and protecting groups of monosaccharides on the ratio of α‐ and β‐N‐arylglycosylamines.

Keywords:

• Synthesis
• N‐Arylglycosylamines
• Configuration

Notes

^aFor compound 7a (white solid). ¹H NMR (CDCl₃, ppm) β‐configuration. δ: 7.26–7.19 (m, 2H, Ar‐H), 6.89 (d, 0.92H, Ar‐H), 6.85 (t, 0.60H, Ar‐H), 6.66 (d, 1.48H, Ar‐H), 5.37 (t, 0.62H, H‐2), 5.08 (dd, 0.62H, J _2–1 = 9.8 Hz, H‐1), 4.77 (d, 0.62H, Gly–NH), 4.30 (m, 1.24H, H‐6), 4.14 (m, 0.62H, H‐3), 4.09 (dd, 0.62H, H‐4), 3.83 (m, 0.62H, H‐5), 2.06–2.03 (4s, 12H, CH₃CO); α‐configuration. δ: 7.26–7.19 (m, 2H, Ar‐H), 6.89 (d, 0.92H, Ar‐H), 6.85 (t, 0.60H, Ar‐H), 6.66 (d, 1.48H, Ar‐H), 5.47 (t, 0.38H, H‐2), 5.21 (dd, 0.38H, J _2–1 = 5.2 Hz, H‐1), 4.44 (br, 0.38H, Gly–NH), 4.30 (m, 0.76H, H‐6), 4.16 (m, 0.38H, H‐3), 4.03 (dd, 0.38H, H‐4), 3.83 (m, 0.38H, H‐5), 2.06–2.03 (4s, 12H, CH₃CO); ¹³C NMR (100 MHz, DMSO‐d ₆): 170.34 (C, CO), 170.04 (C, CO), 169.79 (C, CO), 169.68 (C, CO), 146.28 (C, Ar‐C), 129.24 (2C, Ar‐C), 118.72 (C, Ar‐C), 114.36 (2C, Ar‐C), 82.32 (C, Gly–C), 73.88 (C, Gly–C), 71.50 (C, Gly–C), 68.93 (C, Gly–C), 65.91 (C, Gly–C), 62.36 (C, Gly–C), 20.96 (C, CH₃), 20.90 (C, CH₃), 20.83 (C, CH₃), 20.78 (C, CH₃); MS: m/z, 423 (M⁺). For compound 9a (oil). ¹H NMR (CDCl₃, ppm) β‐configuration. δ: 7.26–7.19 (m, 2H, Ar‐H), 6.85 (t, 1.6H, Ar‐H), 6.7(d, 1.4H, Ar‐H), 5.13–5.05 (m, 0.68H, H‐4), 5.50 (t, 0.68H, H‐2), 4.98 (d, 0.68H, Gly–NH), 4.49 (d, 0.68H, J _2–1 = 9.7 Hz, H‐1), 3.65 (m, 0.68H, H‐5), 2.27–2.00 (3s, 9H, CH₃CO), 1.27 (d, 2.04H, H‐6); α‐configuration. δ: 7.26–7.19 (m, 2H, Ar‐H), 6.85 (t, 1.6H, Ar‐H), 6.7 (d, 1.4H, Ar‐H), 5.13–5.05 (m, 0.64H, Gly–NH and H‐4), 5.36 (t, 0.32H, H‐2), 5.24 (dd, 0.32H, H‐3), 4.38 (d, 0.32H, J _2–1 = 4.5 Hz, H‐1), 4.01 (m, 0.32H, H‐5), 2.27–2.00 (3s, 9H, CH₃CO), 1.23 (d, 0.96H, H‐6); ¹³C NMR(100 MHz, CDCl₃): 170.80 (C, CO), 170.08 (C, CO), 169.92 (C, CO), 144.50 (C, Ar‐C), 120.11 (2C, Ar‐C), 119.69 (C, Ar‐C), 114.48 (2C, Ar‐C), 81.09 (C, Gly‐C), 71.92 (C, Gly‐C), 71.15 (C, Gly‐C), 70.72 (C, Gly‐C), 69.55 (C, Gly‐C), 17.56 (C, Gly‐C), 20.85 (C, CH₃), 20.83 (C, CH₃), 20.55 (C, CH₃); MS: m/z, 365 (M⁺).