3.4. Synthesis of the Mannuronic Acid Containing Trisaccharides
Methyl (2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-(sodium 2,3-di-O-acetyl-β-d-mannopyranosyl-uronate)-(1→4)-α-d-glucopyranoside (4)
Compound 35 (200 mg, 0.192 mmol) was converted to 4 according to general method F. The crude product was purified by silica gel chromatography (1:1 CH2Cl2/MeOH) to give compound 4 (110 mg, 85%) as a white foam. Rf 0.37 (1:1 CH2Cl2/MeOH); + 124.0 (c 0.10, H2O); 1H NMR (700 MHz, D2O) δ = 5.30 (d, J = 3.6 Hz, 1H, H-1′), 5.25–5.23 (m, 2H, H-1″, H-3′), 5.18 (t, J = 3.7 Hz, 1H, H-2′), 4.72 (d, J = 3.8 Hz, 1H, H-1), 4.28 (t, J = 7.2 Hz, 1H, H-4′), 4.20 (d, J = 6.8 Hz, 1H, H-5′), 3.84 (dd, J = 3.9 Hz, J = 12.3 Hz, 1H, H-6a), 3.76 (d, J = 12.8 Hz, 1H, H-6b), 3.75–3.70 (m, 2H, H-3, H-6″a), 3.67–3.64 (m, 3H, H-5, H-5″, H-6″b), 3.57 (t, J = 9.5 Hz, 1H, H-4), 3.53 (s, 3H, OCH3), 3.50–3.48 (m, 2H, H-2, H-3″), 3.47 (s, 3H, OCH3), 3.41 (s, 3H, OCH3), 3.33 (s, 3H, C-1-OCH3), 3.24 (dd, J = 3.7 Hz, J = 10.0 Hz, 1H, H-2″), 3.21 (t, J = 9.7 Hz, 1H, H-4″), 2.08 (s, 3H, Ac-CH3), 2.03 (s, 3H, Ac-CH3) ppm; 13C NMR (176 MHz, D2O) δ = 175.4 (1C, COONa), 173.9, 173.7 (2C, 2 × Cq Ac), 100.1 (1C, C-1), 99.4 (1C, C-1′), 97.2 (1C, C-1″), 82.9 (1C, C-3″), 81.1 (1C, C-2″), 79.3 (1C, C-4″), 78.8 (1C, C-4), 75.8 (1C, C-5′), 74.0 (1C, C-3), 72.9 (1C, C-4′), 72.2 (2C, C-2, C-3′), 71.8 (1C, C-5″), 71.2 (1C, C-5), 70.4 (1C, C-2′), 61.4 (1C, C-6), 61.1 (1C, OCH3), 60.6 (1C, C-6″), 60.5, 59.6 (2C, 2 × OCH3), 56.0 (1C, C-1-OCH3), 21.3, 21.2 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C26H42NaO19 681.2212, found: 681.2209.
Methyl (2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-(sodium β-d-mannopyranosyl-uronate)-(1→4)-α-d-glucopyranoside (5)
Compound 4 (40 mg, 0.058 mmol) was converted to 5 according to general method G. The crude product was purified by silica gel chromatography (1:1 CH2Cl2/MeOH) to give compound 5 (34 mg, 97%) as a white foam. Rf 0.18 (1:1 CH2Cl2/MeOH); + 149.2 (c 0.13, H2O); 1H NMR (700 MHz, D2O) δ = 5.43 (d, J = 3.6 Hz, 1H, H-1″), 5.20 (d, J = 3.7 Hz, 1H, H-1′), 4.69 (d, J = 3.8 Hz, 1H, H-1), 4.17 (d, J = 7.4 Hz, 1H, H-5′), 4.06 (t, J = 7.5 Hz, 1H, H-4′), 3.96 (dd, J = 3.1 Hz, J = 7.7 Hz, 1H, H-3′), 3.82 (t, J = 3.4 Hz, 1H, H-2′), 3.74–3.72 (m, 2H, H-6a,b), 3.71 (t, J = 9.4 Hz, 1H, H-3), 3.67 (dd, J = 1.9 Hz, J = 12.4 Hz, 1H, H-6″a), 3.63 (dd, J = 3.4 Hz, J = 12.5 Hz, 1H, H-6″b), 3.61 (dd, J = 3.2 Hz, J = 6.9 Hz, 1H, H-5), 3.56 (dt, J = 3.0 Hz, J = 10.2 Hz, 1H, H-5″), 3.53 (t, J = 9.6 Hz, 1H, H-4), 3.50 (s, 3H, OCH3), 3.47 (dd, J = 3.7 Hz, J = 9.9 Hz, 1H, H-2), 3.44 (s, 3H, OCH3), 3.43 (t, J = 9.0 Hz, 1H, H-3″), 3.41 (s, 3H, OCH3), 3.30 (s, 3H, C-1-OCH3), 3.22 (dd, J = 3.7 Hz, J = 10.0 Hz, 1H, H-2″), 3.19 (t, J = 9.7 Hz, 1H, H-4″) ppm; 13C NMR (176 MHz, D2O) δ = 175.2 (1C, COONa), 102.1 (1C, C-1′), 100.1 (1C, C-1), 97.0 (1C, C-1″), 82.5 (1C, C-3″), 81.3 (1C, C-2″), 79.4 (1C, C-4″), 78.5 (1C, C-4), 75.4 (1C, C-4′), 74.6 (1C, C-5′), 74.3 (1C, C-3), 72.1 (1C, C-2), 71.8 (1C, C-5″), 71.4 (1C, C-3′), 71.2 (1C, C-5), 71.0 (1C, C-2′), 61.5 (1C, C-6), 61.0 (1C, OCH3), 60.6 (1C, C-6″), 60.6, 58.9 (2C, 2 × OCH3), 56.0 (1C, C-1-OCH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C22H38NaO17 597.2001, found: 597.2002.
Penta-sodium [methyl (2,3,4-tri-O-methyl-6-O-sulphonato-α-d-glucopyranosyl)-(1→4)-(2,3-di-O-acetyl-β-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-sulphonato-α-d-glucopyranoside (6)
Compound 4 (45 mg, 0.066 mmol) was converted to 6 according to general method H. The crude product was purified by Sephadex G-25 gel chromatography in H2O and transformed to Na+ salt using Dowex Na+ ion exchange resin to give 6 (68 mg, 94%) as a white solid. Rf 0.28 (7:6:1 CH2Cl2/MeOH/H2O); + 98.6 (c 0.07, H2O); 1H NMR (700 MHz, D2O) δ = 5.52 (t, J = 2.6 Hz, 1H, H-2′), 5.32 (d, J = 2.0 Hz, 1H, H-1′), 5.25–5.24 (m, 2H, H-1″, H-3′), 5.12 (d, J = 3.5 Hz, 1H, H-1), 4.71–4.68 (m, 1H, H-3), 4.37 (dd, J = 1.8 Hz, J = 11.3 Hz, 1H, H-6a), 4.33 (dd, J = 3.6 Hz, J = 9.9 Hz, 1H, H-2), 4.26–4.24 (m, 1H, H-6″a), 4.23–4.20 (m, 2H, H-4′, H-6b), 4.13–4.11 (m, 2H, H-5′, H-6″b), 4.06–4.04 (m, 1H, H-5), 3.93–3.90 (m, 2H, H-4, H-5″), 3.59 (s, 3H, OCH3), 3.54 (s, 3H, OCH3), 3.53–3.52 (m, 1H, H-3″), 3.45 (s, 6H, 2 × OCH3), 3.30–3.27 (m, 2H, H-2″, H-4″), 2.14, 2.07 (2 × s, 6H, 2 × Ac-CH3) ppm; 13C NMR (176 MHz, D2O) δ = 175.1 (1C, COONa), 173.5, 173.4 (2C, 2 × Cq Ac), 99.9 (1C, C-1′), 97.8 (1C, C-1), 97.7 (1C, C-1″), 82.9 (1C, C-3″), 80.9 (1C, C-2″), 79.3 (1C, C-3), 78.9 (1C, C-4″), 76.6 (1C, C-4), 75.8 (1C, C-2), 75.2 (1C, C-5′), 72.8 (1C, C-3′), 72.6 (1C, C-4′), 70.7 (1C, C-2′), 69.7 (1C, C-5″), 69.0 (1C, C-5), 68.0 (1C, C-6), 66.9 (1C, C-6″), 61.0, 60.8, 59.9 (3C, 3 × OCH3), 56.2 (1C, C-1-OCH3), 21.4, 21.1 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C26H37Na7O31S4 566.9737, found: 566.9737.
Penta-sodium [methyl (2,3,4-tri-O-methyl-6-O-sulphonato-α-d-glucopyranosyl)-(1→4)-(β-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-sulphonato-α-d-glucopyranoside (7)
Compound 6 (45 mg, 0.041 mmol) was converted to 7 according to general method I. The crude product was purified by Sephadex G-25 gel chromatography in H2O and transformed to Na+ salt using Dowex Na+ ion exchange resin to produce 7 (38 mg, 93%) as a white solid. Rf 0.61 (6:6:1 CH2Cl2/MeOH/H2O); + 28.2 (c 0.16, H2O); 1H NMR (700 MHz, D2O) δ = 5.50 (d, J = 3.6 Hz, 1H, H-1″), 5.11 (d, J = 2.1 Hz, 1H, H-1′), 5.07 (d, J = 3.4 Hz, 1H, H-1), 4.59 (d, J = 9.3 Hz, 1H, H-3), 4.30 (dd, J = 2.3 Hz, J = 11.4 Hz, 1H, H-6″a), 4.28 (dd, J = 3.6 Hz, J = 10.0 Hz, 1H, H-2), 4.20 (dd, J = 2.8 Hz, J = 10.4 Hz, 2H, H-6a, H-6″b), 4.08–4.07 (m, 2H, H-2′, H-6b), 3.97–3.95 (m, 4H, H-3′, H-4′, H-5′, H-5), 3.84 (d, J = 10.1 Hz, 1H, H-5″), 3.81 (t, J = 9.3 Hz, 1H, H-4), 3.53 (s, 3H, OCH3), 3.51–3.48 (m, 4H, H-3″, OCH3), 3.45 (s, 3H, OCH3), 3.39 (s, 3H, C-1-OCH3), 3.25 (t, J = 9.8 Hz, 1H, H-4″), 3.24 (dd, J = 4.0 Hz, J = 9.8 Hz, 1H, H-2″) ppm; 13C NMR (176 MHz, D2O) δ = 182.3 (1C, COONa), 103.2 (1C, C-1′), 97.9 (1C, C-1), 96.9 (1C, C-1″), 82.3 (1C, C-3″), 81.1 (1C, C-2″), 79.0 (2C, C-3, C-4″), 77.7 (1C, C-4), 75.9 (1C, C-2), 75.3, 74.7 (2C, C-3′, C-4′), 71.7 (1C, C-5′), 71.3 (1C, C-2′), 69.6 (1C, C-5″), 69.5 (1C, C-5), 68.0 (1C, C-6″), 67.0 (1C, C-6), 61.0, 60.8, 58.9 (3C, 3 × OCH3), 56.2 (1C, C-1-OCH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C22H33Na7O29S4 524.9632, found: 524.9628.
Methyl (2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-(sodium 2,3-di-O-acetyl-α-d-mannopyranosyl-uronate)-(1→4)-α-d-glucopyranoside (8)
Compound 37 (407 mg, 0.391 mmol) was converted to 8 according to general method F. The crude product was purified by silica gel chromatography (1:1 CH2Cl2/MeOH) to produce compound 8 (241 mg, 91%) as a white foam. Rf 0.41 (1:1 CH2Cl2/MeOH); + 116.0 (c 0.10, H2O); 1H NMR (700 MHz, D2O) δ = 5.34 (d, J = 4.1 Hz, 1H, H-1′), 5.28–5.26 (m, 2H, H-1″, H-3′), 5.19 (t, J = 3.5 Hz, 1H, H-2′), 4.73 (d, J = 3.7 Hz, 1H, H-1), 4.32–4.30 (m, 2H, H-4′, H-5′), 3.83 (dd, J = 4.4 Hz, J = 12.4 Hz, 1H, H-6a), 3.78 (dd, J = 1.8 Hz, J = 12.3 Hz, 1H, H-6b), 3.75 (t, J = 9.4 Hz, 1H, H-3), 3.72 (dd, J = 2.0 Hz, J = 12.5 Hz, 1H, H-6″a), 3.69–3.67 (m, 2H, H-5, H-6″b), 3.63–3.58 (m, 2H, H-4, H-5″), 3.55 (s, 3H, OCH3), 3.51–3.48 (m, 2H, H-2, H-3″), 3.48 (s, 3H, OCH3), 3.43 (s, 3H, OCH3), 3.34 (s, 3H, C-1-OCH3), 3.26 (dd, J = 3.8 Hz, J = 10.0 Hz, 1H, H-2″), 3.23 (t, J = 9.7 Hz, 1H, H-4″), 2.09 (s, 3H, Ac-CH3), 2.05 (s, 3H, Ac-CH3) ppm; 13C NMR (176 MHz, D2O) δ = 173.7 (1C, COONa), 172.9, 172.7 (2C, 2 × Cq Ac), 99.1 (1C, C-1), 98.3 (1C, C-1′), 96.4 (1C, C-1″), 82.0 (1C, C-3″), 80.1 (1C, C-2″), 78.3 (1C, C-4″), 77.7 (1C, C-4), 74.2 (1C, C-4′), 73.0 (1C, C-3), 71.8 (1C, C-5′), 71.3 (1C, C-2), 71.0 (2C, C-3′, C-5″), 70.1 (1C, C-5), 69.3 (1C, C-2′), 60.4 (1C, C-6), 60.1 (1C, OCH3), 59.7 (1C, OCH3), 59.6 (1C, C-6″), 58.7 (1C, OCH3), 55.0 (1C, C-1-OCH3), 20.4, 20.2 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C26H42NaO19 681.2212, found: 681.2211.
Methyl (2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-(sodium α-d-mannopyranosyl-uronate)-(1→4)-α-d-glucopyranoside (9)
Compound 8 (42 mg, 0.062 mmol) was converted to 9 according to general method G. The crude product was purified by silica gel chromatography (1:1 CH2Cl2/MeOH) to produce compound 9 (28 mg, 75%) as a white foam. Rf 0.35 (1:1 CH2Cl2/MeOH); + 255.4 (c 0.11, H2O); 1H NMR (700 MHz, D2O) δ = 5.45 (d, J = 3.6 Hz, 1H, H-1″), 5.28 (d, J = 4.3 Hz, 1H, H-1′), 4.72 (d, J = 3.7 Hz, 1H, H-1), 4.40 (d, J = 6.5 Hz, 1H, H-5′), 4.14 (t, J = 6.9 Hz, 1H, H-4′), 4.04 (dd, J = 3.1 Hz, J = 7.1 Hz, 1H, H-3′), 3.85–3.84 (m, 1H, H-2′), 3.80–3.73 (m, 3H, H-3, H-6a,b), 3.71–3.64 (m, 3H, H-5, H-6″a,b), 3.58 (t, J = 9.8 Hz, 1H, H-4), 3.52 (s, 3H, OCH3), 3.51–3.49 (m, 2H, H-2, H-5″), 3.47 (s, 3H, OCH3), 3.43 (s, 3H, OCH3), 3.42–3.39 (m, 1H, H-3″), 3.33 (s, 3H, C-1-OCH3), 3.27–3.22 (m, 2H, H-2″, H-4″) ppm; 13C NMR (176 MHz, D2O) δ = 173.7 (1C, COONa), 101.6 (1C, C-1′), 100.1 (1C, C-1), 97.2 (1C, C-1″), 82.7 (1C, C-3″), 81.1 (1C, C-2″), 79.4 (1C, C-4″), 78.2 (1C, C-4), 75.6 (1C, C-4′), 74.2 (1C, C-3), 73.6 (1C, C-5′), 72.1 (2C, C-2, C-5″), 71.1 (2C, C-3′, C-5), 70.6 (1C, C-2′), 61.5 (1C, C-6), 61.1 (1C, OCH3), 60.8 (1C, OCH3), 60.6 (1C, C-6″), 59.0 (1C, OCH3), 56.1 (1C, C-1-OCH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C22H38NaO17 597.2001, found: 597.1999.
Penta-sodium [methyl (2,3,4-tri-O-methyl-6-O-sulphonato-α-d-glucopyranosyl)-(1→4)-(α-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-sulphonato-α-d-glucopyranoside (11)
Compound 8 (60 mg, 0.088 mmol) was converted to 10 according to general method H. The crude product was purified by Sephadex G-25 gel chromatography in H2O and transformed to Na+ salt using Dowex Na+ ion exchange resin to produce 10 (56 mg, mixture of partially deacetylated compounds) as a white solid. UHR ESI-QTOF (positive ion): m/z calcd for [M + 2Na]2+ C26H37Na7O31S4 566.9737, found: 566.9732. The partially deacetylated mixture of compound 10 (56 mg, 0.051 mmol) was converted to 11 according to general method I. The crude product was purified by Sephadex G-25 gel chromatography in H2O and transformed to Na+ salt using Dowex Na+ ion exchange resin to produce 11 (44 mg, 84% for two steps) as a white solid. Rf 0.74 (6:7:1 CH2Cl2/MeOH/H2O); + 55.6 (c 0.16, H2O); 1H NMR (700 MHz, D2O) δ = 5.54 (d, J = 3.5 Hz, 1H, H-1″), 5.16 (s, 1H, H-1′), 5.11 (d, J = 3.3 Hz, 1H, H-1), 4.63 (t, J = 9.3 Hz, 1H, H-3), 4.34–4.31 (m, 2H, H-2, H-6a), 4.24–4.23 (m, 2H, H-6b, H-6″a), 4.13–4.11 (m, 2H, H-2′, H-6″b), 4.01–3.99 (m, 4H, H-3′, H-4′, H-5′, H-5), 3.89–3.88 (m, 1H, H-5″), 3.85 (t, J = 9.3 Hz, 1H, H-4), 3.57 (s, 3H, OCH3), 3.53 (s, 3H, OCH3), 3.55–3.52 (m, 1H, H-3″), 3.49 (s, 3H, OCH3), 3.43 (s, 3H, C-1-OCH3), 3.30–3.27 (m, 2H, H-2″, H-4″) ppm; 13C NMR (176 MHz, D2O) δ = 176.2 (1C, COONa), 103.2 (1C, C-1′), 97.9 (1C, C-1), 96.9 (1C, C-1″), 82.3 (1C, C-3″), 81.1 (1C, C-2″), 78.9 (2C, C-3, C-4″), 77.7 (1C, C-4), 75.9 (1C, C-2), 75.3 (1C, C-4′), 74.7 (1C, C-5′), 71.7 (1C, C-3′), 71.3 (1C, C-2′), 69.5 (2C, C-5, C-5″), 68.0 (1C, C-6), 67.0 (1C, C-6″), 61.0, 60.8, 58.9 (3C, 3 × OCH3), 56.2 (1C, C-1-OCH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C22H33Na7O29S4 524.9632, found: 524.9630.
Methyl (4-O-acetyl-α-d-glucopyranosyl)-(1→4)-(sodium 2,3-di-O-acetyl-α-d-mannopyranosyl-uronate)-(1→4)-α-d-glucopyranoside (12)
A mixture of compound 39 (264 mg, 0.216 mmol), which was dissolved in EtOH/AcOH (96%, 29:1, 14.0 mL), and Pd/C (10%, 173 mg) was stirred in an autoclave under a H2 atmosphere (10 bar) for 24 h. After 24 h, the catalyst was filtered through a pad of Celite®, washed with MeOH, and the filtrate was concentrated. The crude product was purified by silica gel chromatography (1:1 CH2Cl2/MeOH) to give compound 12 (125 mg, 85%) as a white solid. Rf 0.44 (1:1 CH2Cl2/MeOH); + 172.8 (c 0.09, H2O); 1H NMR (700 MHz, D2O) δ = 5.30 (d, J = 3.7 Hz, 1H, H-1′), 5.25 (dd, J = 3.2 Hz, J = 7.3 Hz, 1H, H-3′), 5.21 (t, J = 3.4 Hz, 1H, H-2′), 5.15 (d, J = 3.9 Hz, 1H, H-1″), 4.76 (d, J = 9.8 Hz, 1H, H-4″), 4.72 (d, J = 3.9 Hz, 1H, H-1), 4.28–4.23 (m, 2H, H-4′, H-5′), 3.86 (dt, J = 3.2 Hz, J = 10.7 Hz, 1H, H-5″), 3.83–3.77 (m, 3H, H-3″, H-6a,b), 3.74 (t, J = 9.5 Hz, 1H, H-3), 3.66 (ddd, J = 2.2 Hz, J = 4.2 Hz, J = 9.9 Hz, 1H, H-5), 3.62–3.56 (m, 2H, H-4, H-6″a), 3.51–3.47 (m, 3H, H-2, H-2″, H-6″b), 3.34 (s, 3H, C-1-OCH3), 2.09, 2.08, 2.02 (3 × s, 9H, 3 × Ac-CH3) ppm; 13C NMR (176 MHz, D2O) δ = 175.3 (1C, COONa), 174.1, 173.8, 173.7 (3C, 3 × Cq Ac), 100.1 (1C, C-1), 100.0 (1C, C-1′), 99.5 (1C, C-1″), 78.6 (1C, C-4), 75.4 (1C, C-5′), 74.0 (1C, C-3), 73.7 (1C, C-4′), 72.3 (2C, C-2, C-3′), 72.0 (1C, C-2″), 71.7 (2C, C-3″, C-4″), 71.2 (1C, C-5), 70.7 (1C, C-5″), 70.5 (1C, C-2′), 61.4 (1C, C-6), 60.7 (1C, C-6″), 55.9 (1C, C-1-OCH3), 21.3, 21.2 (3C, 3 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C25H38NaO20 681.1849, found: 681.1848.
Methyl (α-d-glucopyranosyl)-(1→4)-(sodium α-d-mannopyranosyl-uronate)-(1→4)-α-d-glucopyranoside (13)
Compound 12 (35 mg, 0.051 mmol) was converted to 13 according to general method G. The crude product was purified by silica gel chromatography (1:1 CH2Cl2/MeOH) to give compound 13 (27 mg, 96%) as a white foam. Rf 0.38 (1:1 CH2Cl2/MeOH); + 205.8 (c 0.12, H2O); 1H NMR (700 MHz, D2O) δ = 5.28 (d, J = 2.9 Hz, 1H, H-1′), 5.20 (s, 1H, H-1″), 4.71 (s, 1H, H-1), 4.45 (d, J = 4.7 Hz, 1H, H-5′), 4.14 (t, J = 5.0 Hz, 1H, H-4′), 4.08–4.06 (m, 1H, H-3′), 3.87–3.85 (m, 1H, H-2′), 3.81–3.75 (m, 3H, H-3, H-6a,b), 3.71–3.69 (m, 2H, H-6″a,b), 3.65–3.59 (m, 4H, H-3″, H-4, H-5, H-5″), 3.52–3.50 (m, 1H, H-2), 3.48–3.46 (m, 1H, H-2″), 3.36 (t, J = 9.3 Hz, 1H, H-4″), 3.33 (s, 3H, C-1-OCH3) ppm; 13C NMR (176 MHz, D2O) δ = 172.6 (1C, COONa), 100.5 (1C, C-1′), 99.2 (1C, C-1), 99.1 (1C, C-1″), 77.5 (1C, C-3″), 75.7 (1C, C-4′), 73.1 (1C, C-3), 72.9 (1C, C-5′), 72.7 (1C, C-5), 72.3 (1C, C-5″), 71.4 (1C, C-2″), 71.1 (1C, C-2), 70.1 (1C, C-4), 69.7 (1C, C-3′), 69.3 (1C, C-2′), 69.1 (1C, C-4″), 60.6 (1C, C-6), 60.1 (1C, C-6″), 55.0 (1C, C-1-OCH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C19H32NaO17 555.1532, found: 555.1532.
Hepta-sodium [methyl (4-O-acetyl-2,3,6-tri-O-sulphonato-α-d-glucopyranosyl)-(1→4)-(2,3-di-O-acetyl-α-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-sulphonato-α-d-glucopyranoside (14)
Compound 12 (52 mg, 0.076 mmol) was converted to 14 according to general method H. The crude product was purified by Sephadex G-25 gel chromatography in H2O and transformed to Na+ salt using Dowex Na+ ion exchange resin to give 14 (96 mg, 89%) as a white solid. Rf 0.63 (6:7:1 CH2Cl2/MeOH/H2O); + 94.2 (c 0.12, H2O); 1H NMR (700 MHz, D2O) δ = 5.53 (t, J = 2.7 Hz, 1H, H-3′), 5.51 (d, J = 3.7 Hz, 1H, H-1″), 5.30 (d, J = 2.3 Hz, 1H, H-1′), 5.27 (dd, J = 3.1 Hz, J = 8.9 Hz, 1H, H-2′), 5.11 (d, J = 3.5 Hz, 1H, H-1), 5.09 (t, J = 9.8 Hz, 1H, H-4″), 4.68 (t, J = 9.4 Hz, 1H, H-3), 4.59 (t, J = 9.7 Hz, 1H, H-3″), 4.37 (dd, J = 1.8 Hz, J = 11.5 Hz, 1H, H-6a), 4.31 (dd, J = 3.5 Hz, J = 9.9 Hz, 1H, H-2), 4.29–4.23 (m, 3H, H-4′, H-5′, H-6a), 4.20–4.18 (m, 2H, H-2″, H-5″), 4.15 (dd, J = 2.0 Hz, J = 11.4 Hz, 1H, H-6″a), 4.09 (dd, J = 1.6 Hz, J = 11.6 Hz, 1H, H-6″b), 4.04 (ddd, J = 1.9 Hz, J = 5.6 Hz, J = 9.7 Hz, 1H, H-5), 3.92 (t, J = 9.2 Hz, 1H, H-4), 3.43 (s, 3H, C-1-OCH3), 2.11, 2.06, 2.02 (3 × s, 9H, 3 × Ac-CH3) ppm; 13C NMR (176 MHz, D2O) δ = 174.3 (1C, COONa), 173.1, 172.7 (3C, 3 × Cq Ac), 99.1 (1C, C-1′), 96.9 (1C, C-1), 96.7 (1C, C-1″), 78.5 (1C, C-3), 75.9 (2C, C-3″, C-4), 75.0 (1C, C-2), 74.6 (1C, C-2″), 74.4 (1C, C-4′), 71.8 (2C, C-2′, C-5′), 69.7 (1C, C-3′), 68.2 (1C, C-5), 67.8 (1C, C-4″), 67.7 (1C, C-5″), 67.2 (1C, C-6), 65.5 (1C, C-6″), 55.4 (1C, C-1-OCH3), 20.9, 20.6, 20.3 (3C, 3 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C25H31Na9O38S6 668.8943, found: 668.8943.
Hepta-sodium [methyl (2,3,6-tri-O-sulphonato-α-d-glucopyranosyl)-(1→4)-(α-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-sulphonato-α-d-glucopyranoside (15)
Compound 14 (48 mg, 0.037 mmol) was converted to 15 according to general method I. The crude product was purified by Sephadex G-25 gel chromatography in H2O and transformed to Na+ salt using Dowex Na+ ion exchange resin to give 15 (37 mg, 86%) as a white solid. Rf 0.41 (6:7:1 CH2Cl2/MeOH/H2O); + 64.0 (c 0.10, H2O); 1H NMR (700 MHz, D2O) δ = 5.60 (d, J = 3.7 Hz, 1H, H-1″), 5.16 (d, J = 2.1 Hz, 1H, H-1′), 5.09 (d, J = 3.5 Hz, 1H, H-1), 4.61 (t, J = 9.3 Hz, 1H, H-3), 4.52 (t, J = 9.5 Hz, 1H, H-3″), 4.38 (dd, J = 2.1 Hz, J = 11.8 Hz, 1H, H-6a), 4.33–4.29 (m, 2H, H-2, H-6″a), 4.23–4.21 (m, 2H, H-2″, H-6b), 4.16–4.14 (m, 1H, H-6″b), 4.08–4.07 (m, 4H, H-2′, H-3′, H-4′, H-5′), 4.01–3.98 (m, 1H, H-5), 3.97–3.95 (m, 1H, H-5″), 3.86 (t, J = 9.3 Hz, 1H, H-4), 3.71 (t, J = 9.6 Hz, 1H, H-4″), 3.40 (s, 3H, C-1-OCH3) ppm; 13C NMR (176 MHz, D2O) δ = 175.1 (1C, COONa), 101.8 (1C, C-1′), 97.0 (2C, C-1, C-1″), 78.4 (1C, C-3″), 78.0 (1C, C-3), 76.7 (1C, C-4), 75.6 (1C, C-4′), 75.1 (1C, C-2″), 75.0 (1C, C-2), 74.7 (1C, C-5′), 70.1 (2C, C-2′, C-3′), 69.7 (1C, C-5″), 68.6 (1C, C-5), 67.9 (1C, C-4″), 67.2 (1C, C-6), 66.1 (1C, C-6″), 55.3 (1C, C-1-OCH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C19H25Na9O35S6 605.8784, found: 605.8784.
Phenyl 2,3-di-O-acetyl-4,6-O-(2-naphthyl)methylidene-1-thio-α-d-mannopyranoside (17)
To a stirred solution of compound
16 [
58] (13.2 g, 0.032 mol) in dry pyridine (200 mL), Ac
2O (80.0 mL, 0.845 mol, 26.3 equiv.) was added at 0 °C and the reaction mixture was stirred for 24 h at room temperature. After 24 h, all volatiles were removed by reduced pressure and the residue was dissolved in CH
2Cl
2 (500 mL), washed with H
2O (2 × 250 mL), 1M aqueous solution of H
2SO
4 (2 × 250 mL), H
2O (2 × 250 mL), saturated aqueous solution of NaHCO
3 (2 × 250 mL), and H
2O (2 × 250 mL) until neutral pH. The organic layer was dried over MgSO
4, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel chromatography (6:4
n-hexane/EtOAc) to give
17 (11,24 g, 71%) as a colourless syrup.
Rf 0.52 (6:4
n-hexane/EtOAc);
+ 96.0 (
c 0.30, CHCl
3);
1H NMR (500 MHz, CDCl
3)
δ = 7.95–7.23 (m, 12H, arom.), 5.75 (s, 1H, H
ac), 5.64 (dd,
J = 1.3 Hz,
J = 3.4 Hz, 1H, H-2), 5.47–5.45 (m, 2H, H-1, H-3), 4.53 (dt,
J = 5.0 Hz,
J = 9.9, Hz, 1H, H-5), 4.30 (dd,
J = 4.9 Hz,
J = 10.4 Hz, 1H, H-6a), 4.20 (t,
J = 10.0 Hz, 1H, H-4), 3.93 (t,
J = 10.3 Hz, 1H, H-6b), 2.17, 2.03 (2 × s, 6H, 2 × Ac-C
H3) ppm;
13C NMR (125 MHz, CDCl
3)
δ = 169.9, 169.8 (2C, 2 × Ac-
C=O), 134.5, 133.8, 133.0, 132.9 (4C, 4 × C
q arom.), 132.4–123.9 (12C, arom.), 102.3, (1C, C
ac), 87.0 (1C, C-1), 76.4 (1C, C-4), 71.6 (1C, C-2), 68.7 (1C, C-3), 68.6 (1C, C-6), 65.3 (1C, C-5), 21.0, 20.9 (2C, 2 × Ac-
CH
3) ppm; UHR ESI-QTOF (positive ion):
m/
z calcd. for [M + Na]
+ C
27H
26NaO
7S 517.1291, found: 517.1291.
Phenyl 2,3-di-O-(tert-buthyl-dimethyl-silyl)-4,6-O-(2-naphthyl)methylidene-1-thio-α-d-mannopyranoside (18)
To a cooled (−20 °C) solution of
16 [
58] (2.0 g, 4.877 mmol) in dry CH
2Cl
2 (40.7 mL), Et
3N (5.64 mL, 40.48 mmol, 8.3 equiv.) and TBDMSOTf (5.6 mL, 24.38 mmol, 5.0 equiv.) were added. The mixture was allowed to warm up to room temperature and stirred for 3 h. After 3 h, CH
2Cl
2 (113 mL) and water (56 mL) were added and stirred for 15 min. After separation of the phases, the organic layer was dried over MgSO
4 and filtered, and the filtrate was evaporated. The crude product was purified by silica gel chromatography (98:2
n-hexane/acetone) to produce
18 (3.01 g, 96%) as a colourless syrup.
Rf 0.52 (1:1 CH
2Cl
2/
n-hexane);
+ 116.7 (
c 0.15, CHCl
3);
1H NMR (500 MHz, CDCl
3)
δ = 7.95–7.18 (m, 12H, arom.), 5.66 (s, 1H, H
ac), 5.32 (s, 1H, H-1), 4.29 (dt,
J = 4.9 Hz,
J = 9.4 Hz, 1H, H-5), 4.21 (dd,
J = 4.6 Hz,
J = 10.0 Hz, 1H, H-6a), 4.14 (bs, 1H, H-2), 4.10 (dd,
J = 2.6 Hz,
J = 9.1 Hz, 1H, H-3), 4.05 (t,
J = 9.1 Hz, 1H, H-4), 3.82 (t,
J = 10.1 Hz, 1H, H-6b), 0.90, 0.86 (2 × s, 18H, 6 ×
t-Bu-C
H3), 0.11, 0.07, 0.05, 0.04 (4 × s, 12H, 4 × Si-C
H3) ppm;
13C NMR (125 MHz, CDCl
3)
δ = 135.2, 134.2, 133.7, 133.1 (4C, 4 × C
q arom.), 131.9–124.2 (12C, arom.), 102.3, (1C, C
ac), 90.5 (1C, C-1), 79.5 (1C, C-4), 75.3 (1C, C-2), 70.8 (1C, C-3), 68.9 (1C, C-6), 66.0 (1C, C-5), 26.2 (5C, 5 × Si-
CH
3), 25.9 (5C, 5 × Si-
CH
3), 18.6, 18.2 (2C, 2 × C
q Si-
t-Bu) ppm; UHR ESI-QTOF (positive ion):
m/
z calcd. for [M + Na]
+ C
35H
50NaO
5SSi
2 661.2810, found: 661.2809.
Methyl [2,3-di-O-acetyl-4,6-O-(2-naphthyl)methylidene-α-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (20)
Compound
19 [
64] (5.09 g, 10.96 mmol) was glycosylated with
17 (8.13 g, 16.435 mmol, 1.5 equiv.) according to general method A. The crude product was purified by silica gel chromatography (98:2 CH
2Cl
2/EtOAc) to produce
20 (8.59 g, 92%) as a colourless syrup.
Rf 0.32 (98:2 CH
2Cl
2/EtOAc);
+ 32.5 (
c 0.36, CHCl
3);
1H NMR (500 MHz, CDCl
3)
δ = 7.91–7.22 (m, 22H, arom.), 5.68 (s, 1H, H
ac), 5.42–5.41 (m, 2H, H-1′, H-2′), 5.37 (dd,
J = 2.9 Hz,
J = 9.9 Hz, 1H, H-3′), 5.06 (d,
J = 11.2 Hz, 1H, Bn-C
H2a), 4.72–4.56 (m, 6H, 2 × Bn-C
H2, Bn-C
H2b, H-1), 4.13 (dd,
J = 4.4 Hz,
J = 10.3 Hz, 1H, H-5′), 4.06–3.98 (m, 3H, H-3, H-4′, H-5), 3.95 (t,
J = 9.0 Hz, 1H, H-4), 3.84–3.76 (m, 3H, H-6′a,b, H-6a), 3.71–3.70 (m, 1H, H-6b), 3.56 (dd,
J = 3.4 Hz,
J = 9.5 Hz, 1H, H-2), 3.39 (s, 3H, C-1OC
H3), 1.99, 1.96 (2 × s, 6H, 2 × Ac-C
H3) ppm;
13C NMR (125 MHz, CDCl
3)
δ = 170.0, 169.5 (2C, 2 × C
q Ac), 138.6, 138.1, 138.0, 134.6, 133.8, 132.9 (6C, 6 × C
q arom.), 128.6–123.9 (22C, arom.), 102.1, (1C, C
ac), 99.7 (1C, C-1′), 97.9 (1C, C-1), 81.9 (1C, C-3), 80.3 (1C, C-2), 76.1 (1C, C-4′), 75.2, (1C, Bn-
CH
2), 74.7 (1C, C-4), 73.7, 73.3 (2C, 2 × Bn-
CH
2), 70.2 (1C, C-2′), 69.4 (1C, C-5′), 69.0, 68.7 (2C, C-6, C-6′), 68.5 (1C, C-3′), 64.9 (1C, C-5), 55.4 (1C, C-1-O
CH
3), 20.9, 20.7 (2C, 2 × Ac-
CH
3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [C
49H
52O
13 + Na]
+: 871.3300; found: 871.3297.
Methyl [2,3-di-O-acetyl-4,6-O-(2-naphthyl)methylidene-α-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (21)
Reaction 1.: Compound 20 (623 mg, 0.735 mmol) was converted to 21 by general method B. The crude product was purified by silica gel chromatography (6:4 n-hexane/EtOAc) to produce compound 21 (463 mg, 66%) as a white foam.
Reaction 2.: Compound 20 (607 mg, 0.715 mmol) was converted to 21 by general method C. The crude product was purified by silica gel chromatography (55:45 n-hexane/EtOAc, then 6:4 hexane/acetone) to produce compound 21 (439 mg, 72%) as a white foam. Rf 0.44 (6:4 n-hexane/EtOAc); + 32.4 (c 0.33, CHCl3); 1H NMR (500 MHz, CDCl3) δ = 7.81–7.22 (m, 22H, arom.), 5.39 (s, 1H, H-1′), 5.28 (bs, 1H, H-2′), 5.12 (dd, J = 3.1 Hz, J = 9.9 Hz, 1H, H-3′), 5.04 (d, J = 11.1 Hz, 1H, Bn-CH2a), 4.71–4.45 (m, 8H, NAP-CH2, 2 × Bn-CH2, Bn-CH2b, H-1), 3.99–3.96 (m, 2H, H-3, H-4′), 3.86 (t, J = 9.1 Hz, 1H, H-4), 3.80–3.74 (m, 3H, H-5, H-5′, H-6a), 3.68–3.64 (m, 2H, H-6b, H-6′a), 3.57–3.52 (m, 2H, H-2, H-6′b), 3.38 (s, 3H, C-1OCH3), 2.60 (s, 1H, H-4-OH), 2.02, 1.91 (2 × s, 6H, 2 × Ac-CH3) ppm; 13C NMR (125 MHz, CDCl3) δ = 170.7, 169.6 (2C, 2 × Cq Ac), 138.6, 138.3, 138.0, 135.2, 133.3, 133.1 (6C, 6 × Cq arom.), 128.5–125.7 (22C, arom.), 98.9 (1C, C-1′), 97.9 (1C, C-1), 81.8 (1C, C-3), 80.2 (1C, C-2), 75.2, (1C, Bn-CH2), 75.1 (1C, C-4′), 73.8, 73.3 (3C, NAP-CH2, 2 × Bn-CH2), 71.8, 71.7 (2C, C-3′, C-4), 70.3 (1C, C-6′), 69.7 (1C, C-5′), 69.5 (1C, C-2′), 69.1 (1C, C-6), 67.2 (1C, C-5), 55.4 (1C, C-1-OCH3), 21.0, 20.7 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [C49H54O13 + Na]+: 873.3457; found: 873.3458.
Methyl [2,3-di-O-(tert-buthyl-dimethyl-silyl)-4,6-O-(2-naphthyl)methylidene-β-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (22)
A mixture of the thiomannosyl donor
18 (193 mg, 0.302 mmol), BSP (76 mg, 0.362 mmol, 1.2 equiv.), TTBP (150 mg, 0.604 mmol, 2 equiv.), and 4 Å molecular sieves (419 mg) in dry CH
2Cl
2 (4.2 mL) was stirred under an atmosphere of Argon for 1 h. The reaction was cooled to −60 °C and Tf
2O (61 µL, 0.362 mmol, 1.2 equiv.) was added. After 30 min of stirring at −60 °C, a solution of the acceptor
19 [
64] (88 mg, 0.189 mmol, 1.0 equiv.) in dry CH
2Cl
2 (1.4 mL) was added. The reaction mixture was stirred for further 3 h, at −60 °C. After 3 h, the reaction mixture was quenched by the addition of pyridine (745 μL). The mixture was filtered, and the filtrate was washed with saturated aqueous solution of NaHCO
3 (25 mL) and brine (25 mL). The organic phase was dried (MgSO
4) and filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by silica gel chromatography (CH
2Cl
2) to produce
22 (131 mg, 68%) as a white foam.
Rf 0.41 (8:2
n-hexane/acetone);
– 1.82 (
c 0.11, CHCl
3);
1H NMR (500 MHz, CDCl
3)
δ = 7.49–6.71 (m, 22H, arom.), 5.21 (s, 1H, H
ac), 4.51 (s, 1H, H-1′), 4.29 (d,
J = 11.6 Hz, 1H, Bn-C
H2a), 4.15 (d,
J = 12.0 Hz, 3H, Bn-C
H2, H-1), 4.05 (dd,
J = 18.0 Hz,
J = 11.8 Hz, 3H, Bn-C
H2b, Bn-C
H2), 3.65 (ddd,
J = 3.0 Hz,
J = 9.8 Hz,
J = 16.5, 2H, H-6′a, H-3′), 3.53 (t,
J = 9.3 Hz, 1H, H-4′), 3.47–3.37 (m, 3H, H-2′, H-3, H-5′), 3.36–3.26 (m, 5H, H-6′a, H-6a,b, H-5, H-4), 3.10 (dd,
J = 3.5 Hz,
J = 9.5, 1H, H-2), 2.91 (s, 3H, OC
H3), 0.38 (s, 18H, 6 × C
H3 Si-
t-Bu), −0.43 (s, 3H, Si-C
H3), −0.44 (s, 3H, Si-C
H3), −0.53 (s, 3H, Si-C
H3), −0.65 (s, 3H, Si-C
H3) ppm;
13C NMR (125 MHz, CDCl
3)
δ = 139.0, 138.2, 138.1, 135.3, 133.7, 133.0 (6C, C
q arom.), 128.5–124.2 (22C, arom.), 104.3 (1C, C-1′), 102.3 (1C, C
ac), 97.9 (1C, C-1), 81.3 (1C, C-2′), 80.2 (1C, C-2), 79.6 (1C, C-4′), 78.4 (1C, C-4), 74.9 (1C, Bn-
CH
2), 74.2 (1C, C-3), 73.8, 73.3 (2C, 2 × Bn-
CH
2), 70.0 (1C, C-3′), 69.7 (1C, C-5), 69.2 (2C, C-6, C-6′), 65.6 (1C, C-5′), 55.4 (1C, O
CH
3), 26.2 (5C, 5 × Si-
CH
3), 25.9 (5C, 5 × Si-
CH
3), 18.6 (2C, 2 × C
q Si-
t-Bu) ppm; MALDI-TOF-MS (positive ion):
m/
z calcd. for [M + Na]
+ C
57H
76NaO
11SSi
2 1015.4824, found: 1015.4819.
Methyl [4,6-O-(2-naphthyl)methylidene-β-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (23)
Compound 22 (1.473 g, 1.483 mmol) was dissolved in dry THF (30 mL), and the reaction mixture was cooled to 0 °C. After, 1M solution of TBAF in dry THF (5.936 mL, 5.936 mmol, 2 equiv./OH) was added and the reaction mixture was stirred for 48 h at room temperature. After 48 h, the reaction mixture was diluted with EtOAc (500 mL) and washed with water (150 mL) and brine (150 mL). The organic layer was dried over MgSO4 and filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by silica gel chromatography (6:4 n-hexane/acetone) to give 23 (813 mg, 72%) as a white crystal. Rf 0.21 (65:35 n-hexane/acetone); + 38.9 (c 0.18, CHCl3); M.p.: 203–205 °C; 1H NMR (500 MHz, CDCl3) δ = 7.94–7.22 (m, 22H, arom.), 5.64 (s, 1H, Hac), 5.33 (s, 1H, H-1′), 5.06 (d, J = 11.1 Hz, 1H, Bn-CH2a), 4.72 (d, J = 12.0 Hz, 1H, Bn-CH2a), 4.66–4.53 (m, 4H, Bn-CH2b, H-1, BnCH2), 4.54 (d, J = 11.9 Hz, 1H, Bn-CH2b), 4.11 (dd, J = 4.5 Hz, J = 10.1 Hz, 1H, H-6′a), 3.96 (dd, J = 3.4 Hz, J = 9.5 Hz, 1H, H-3′), 3.94–3.89 (m, 2H, H-3, H-4′), 3.87–3.81 (m, 2H, H-2′, H-5′), 3.80 (t, J = 7.2 Hz, 1H, H-4), 3.76–3.69 (m, 4H, H-5, H-6a,b, H-6′b), 3.54 (dd, J = 3.5 Hz, J = 9.6 Hz, 1H, H-2), 3.39 (s, 3H, OCH3), 2.68–2.24 (m, 2H, 2 × OH) ppm; 13C NMR (125 MHz, CDCl3) δ = 138.6, 138.1, 138.0, 134.7, 133.8, 133.0 (6C, Cq arom.), 128.7–123.9 (22C, arom.), 102.3 (1C, Cac), 102.0 (1C, C-1′), 97.9 (1C, C-1), 82.1 (1C, C-3), 80.3 (1C, C-2), 78.9 (1C, C-4′), 76.3 (1C, C-4), 75.8, 73.8, 73.3 (3C, 3 × BnCH2), 71.4 (1C, C-2′), 69.7 (1C, C-5), 69.2 (1C, C-6), 68.8 (1C, C-6′), 68.5 (1C, C-3′), 64.2 (1C, C-5′), 55.4 (1C, OCH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + Na]+ C45H48NaO11 787.3089, found: 787.3083.
Methyl [2,3-di-O-acetyl-4,6-O-(2-naphthyl)methylidene-β-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (24)
To a solution of 23 (614 mg, 0.803 mmol) in dry pyridine (4.0 mL), Ac2O (2.0 mL) was added at 0 °C and the reaction mixture was stirred at room temperature for 24 h. After 24 h, the reaction mixture was concentrated under reduced pressure. The crude product was purified by silica gel chromatography (6:4 n-hexane/acetone) to produce 24 (620 mg, 91%) as a white foam. Rf 0.52 (6:4 n-hexane/acetone); + 44.5 (c 0.11, CHCl3); 1H NMR (500 MHz, CDCl3) δ = 7.91–7.21 (m, 22H, arom.), 5.68 (s, 1H, Hac), 5.43 (s, 2H, H-1′, H-2′), 5.38 (d, J = 10.0 Hz, 1H, H-3′), 5.07 (d, J = 11.2 Hz, 1H, Bn-CH2a), 4.71–4.56 (m, 6H, Bn-CH2b, H-1, 2 × BnCH2), 4.14 (dd, J = 4.1 Hz, J = 10.2 Hz, 1H, H-6′a), 4.07–3.93 (m, 4H, H-3, H-4, H-4′, H-5′), 3.83–3.76 (m, 3H, H-5, H-6′b, H-6a), 3.70 (d, J = 9.2 Hz, 1H, H-6b), 3.56 (dd, J = 3.4 Hz, J = 9.4 Hz, 1H, H-2), 3.39 (s, 3H, OCH3), 1.98, 1.96 (2 × s, 6H, 2 × Ac-CH3) ppm; 13C NMR (125 MHz, CDCl3) δ = 170.0, 169.4 (2C, 2 × Cq Ac), 138.6, 138.1, 138.0, 134.6, 133.7, 132.9 (6C, Cq arom.), 128.5–123.8 (22C, arom.), 102.1 (1C, Cac), 99.6 (1C, C-1′), 97.9 (1C, C-1), 81.9 (1C, C-3), 80.2 (1C, C-2), 76.0 (1C, C-4′), 75.2 (1C, Bn-CH2), 74.7 (1C, C-4), 73.6, 73.3 (2C, 2 × BnCH2), 70.1 (1C, C-2′), 69.4 (1C, C-5), 68.9 (1C, C-6), 68.7 (1C, C-6′), 68.5 (1C, C-3′), 64.9 (1C, C-5′), 55.4 (1C, OCH3), 20.9, 20.7 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + Na]+ C49H52NaO13 871.3300, found: 871.3308.
Methyl [2,3-di-O-acetyl-6-O-(2-naphthyl)methyl-β-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (25)
Reaction 1.: Compound 24 (150 mg, 0.177 mmol) was converted to 25 by general method B. The crude product was purified by silica gel chromatography (55:45 n-hexane/EtOAc, then 6:4 n-hexane/acetone) to give compound 25 (94 mg, 62%) as a white foam.
Reaction 2.: Compound 24 (153 mg, 0.180 mmol) was converted to 25 by general method C. The crude product was purified by silica gel chromatography (65:35 n-hexane/acetone) to produce compound 25 (117 mg, 76%) as a white foam. Rf 0.46 (65:35 n-hexane/acetone); + 44.5 (c 0.11, CHCl3); 1H NMR (500 MHz, CDCl3) δ = 7.82–7.07 (m, 22H, arom.), 5.39 (d, J = 1.9 Hz, 1H, H-1′), 5.30 (dd, J = 1.8 Hz, J = 3.4 Hz, 1H, H-2′), 5.13 (dd, J = 3.3 Hz, J = 9.9 Hz, 1H, H-3′), 5.03 (d, J = 11.1 Hz, 1H, Bn-CH2a), 4.74–4.40 (m, 8H, Bn-CH2b, 2 × Bn-CH2, NAP-CH2, H-1), 3.98 (t, J = 9.1 Hz, 2H, H-3, H-4′), 3.86 (t, J = 9.2 Hz, 1H, H-4), 3.82–3.72 (m, 3H, H-5′, H-5, H-6a), 3.71–3.61 (m, 2H, H-6b, H-6′a), 3.54 (ddd, J = 4.0 Hz, J = 9.9 Hz, J = 17.8 Hz, 2H, H-6′b, H-2), 3.37 (s, 3H, OCH3), 2.72 (s, 1H, H-4′-OH), 2.00 (s, 3H, Ac-CH3), 1.90 (s, 3H, Ac-CH3) ppm; 13C NMR (125 MHz, CDCl3) δ = 170.7, 169.6 (2C, 2 × Cq Ac), 138.5, 138.3, 138.0, 135.2, 133.2, 133.0 (6C, Cq arom.), 128.5–125.6 (22C, arom.), 98.9 (1C, C-1′), 97.8 (1C, C-1), 81.8 (1C, C-3), 80.2 (1C, C-2), 75.2 (1C, C-4), 75.1, 73.8, 73.2, 73.2 (4C, 3 × Bn-CH2, NAP-CH2), 71.8 (2C, C-5′, C-3′), 70.2 (1C, C-6′), 69.7 (1C, C-2′), 69.5 (1C, C-5), 69.1 (1C, C-6), 67.0 (1C, C-4′), 55.3 (1C, C-1-OCH3), 20.9, 20.7 (2C, 2 × Ac-CH3) ppm; MALDI-TOF-MS (positive ion): m/z calcd. for [M + Na]+ C49H54NaO13 873.3462, found: 873.3461.
Methyl (6-O-benzyl-2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-[2,3-di-O-acetyl-6-O-(2-naphthyl)methyl-α-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (27)
Disaccharide acceptor
21 (1.042 g, 1.225 mmol) was glycosylated with
26 [
65] (0.842 g, 2.082 mmol, 1.7 equiv.) according to general method A. The crude product was purified by silica gel chromatography (7:3
n-hexane/acetone) to give
27 (1.055 g, 75%) as a colourless syrup.
Rf 0.49 (7:3
n-hexane/acetone);
+ 40.7 (
c 0.70, CHCl
3);
1H NMR (500 MHz, CDCl
3)
δ = 7.80–7.13 (m, 27H, arom.), 5.43 (d,
J = 9.3 Hz, 1H, H-3′), 5.34 (s, 1H, H-1′), 5.30–5.28 (m, 2H, H-1″, H-2′), 5.03 (d,
J = 11.0 Hz, 1H, Bn-C
H2a), 4.75 (d,
J = 11.0 Hz, 1H, Bn-C
H2b), 4.71–4.43 (m, 7H, H-1, NAP-C
H2, 2 × Bn-C
H2), 4.32 (d,
J = 12.1 Hz, 1H, Bn-C
H2a), 4.21 (t,
J = 9.3 Hz, 1H, H-4′), 4.10 (d,
J = 12.1 Hz, 1H, Bn-C
H2b), 3.99–3.93 (m, 2H, H-3, H-5′), 3.83 (t,
J = 9.0 Hz, 1H, H-4), 3.78–3.75 (m, 3H, H-5, H-6a, H-6′a), 3.71 (d,
J = 9.7 Hz, 1H, H-6b), 3.59 (s, 4H, H-6′b, OC
H3), 3.53 (t,
J = 8.1 Hz, 2H, H-2, H-5″), 3.44 (s, 3H, OC
H3), 3.43–3.38 (m, 1H, H-3″), 3.39 (s, 6H, 2 × OC
H3), 3.36–3.34 (m, 1H, H-6″a), 3.22–3.18 (m, 2H, H-4″, H-6″b), 3.11 (dd,
J = 3.3 Hz,
J = 9.6 Hz, 1H, H-2″), 1.96 (s, 3H, Ac-C
H3), 1.93 (s, 3H, Ac-C
H3) ppm;
13C NMR (125 MHz, CDCl
3)
δ = 169.6 (2C, 2 × C
q Ac), 138.6, 138.3, 138.0, 136.0, 133.3, 133.0 (7C, C
q arom.), 128.5–125.8 (27C, arom.), 99.2 (1C, C-1′), 97.8 (1C, C-1), 97.1 (1C, C-1″), 83.4 (1C, C-3″), 81.5 (2C, C-2″, C-3), 80.2 (1C, C-2), 79.2 (1C, C-4″), 76.8 (1C, C-4), 75.2, 73.6, 73.3, 73.2 (5C, 4 × Bn-
CH
2, NAP-
CH
2), 72.1 (1C, C-3′), 72.0 (1C, C-5′), 71.0 (1C, C-5″), 70.2 (2C, C-2′, C-4′), 69.5 (1C, C-5), 69.2 (2C, C-6, C-6′), 68.1 (1C, C-6″), 60.7, 60.4, 59.2 (3C, 3 × O
CH
3), 55.3 (1C, C-1-O
CH
3), 21.0, 20.7 (2C, 2 × Ac-
CH
3) ppm; UHR ESI-QTOF (positive ion):
m/
z calcd. for [M + Na]
+ C
65H
76NaO
18 1167.4924, found: 1167.4922.
Methyl (6-O-benzyl-2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-[2,3-di-O-acetyl-6-O-(2-naphthyl)methyl-β-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (28)
Disaccharide acceptor
25 (350 mg, 0.411 mmol) was glycosylated with
26 [
65] (283 mg, 0.699 mmol, 1.7 equiv.) according to general method A. The crude product was purified by silica gel chromatography (7:3
n-hexane/acetone) to give
28 (420 mg, 89%) as a colourless syrup.
Rf 0.49 (7:3
n-hexane/acetone);
+ 78.0 (
c 0.10, CHCl
3);
1H NMR (700 MHz, CDCl
3)
δ = 7.81–7.13 (m, 27H, arom.), 5.43 (dd,
J = 3.1 Hz,
J = 9.0 Hz, 1H, H-3′), 5.34 (s, 1H, H-1′), 5.30–5.29 (m, 1H, H-2′), 5.28 (d,
J = 3.7 Hz, 1H, H-1″), 5.03 (d,
J = 11.0 Hz, 1H, Bn-C
H2a), 4.75 (d,
J = 10.9 Hz, 1H, Bn-C
H2b), 4.70–4.44 (m, 7H, H-1, NAP-C
H2, 2 × Bn-C
H2), 4.32 (d,
J = 12.1 Hz, 1H, Bn-C
H2a), 4.21 (t,
J = 9.3 Hz, 1H, H-4′), 4.10 (d,
J = 12.1 Hz, 1H, Bn-C
H2b), 3.97 (t,
J = 9.1 Hz, 1H, H-3), 3.95–3.94 (m, 1H, H-5′), 3.83 (t,
J = 9.2 Hz, 1H, H-4), 3.78–3.76 (m, 3H, H-5, H-6′ab), 3.71–3.70 (m, 1H, H-6a), 3.59 (s, 4H, H-6b, OC
H3), 3.54–3.50 (m, 2H, H-2, H-5″), 3.43 (s, 3H, OC
H3), 3.42–3.41 (m, 1H, H-3″), 3.39 (s, 6H, 2 × OC
H3), 3.37–3.34 (m, 1H, H-6″a), 3.22–3.19 (m, 2H, H-4″, H-6″b), 3.11 (dd,
J = 3.8 Hz,
J = 9.8 Hz, 1H, H-2″), 1.96 (s, 3H, Ac-C
H3), 1.93 (s, 3H, Ac-C
H3) ppm;
13C NMR (176 MHz, CDCl
3)
δ = 169.6, 169.5 (2C, 2 × C
q Ac), 138.6, 138.3, 138.0, 137.9, 136.0, 133.3, 132.9 (7C, C
q arom.), 128.5–125.8 (27C, arom.), 99.2 (1C, C-1′), 97.8 (1C, C-1), 97.1 (1C, C-1″), 83.3 (1C, C-3″), 81.5 (2C, C-2″, C-3), 80.1 (1C, C-2), 79.2 (1C, C-4″), 76.8 (1C, C-4), 75.2, 73.6, 73.3, 73.2 (5C, 4 × Bn-
CH
2, NAP-
CH
2), 72.0 (1C, C-3′), 72.0 (1C, C-5′), 71.0 (1C, C-5″), 70.2 (2C, C-2′, C-4′), 69.5 (1C, C-5), 69.2 (2C, C-6, C-6′), 68.1 (1C, C-6″), 60.7, 60.4, 59.2 (3C, 3 × O
CH
3), 55.3 (1C, C-1-O
CH
3), 21.0, 20.7 (2C, 2 × Ac-
CH
3) ppm; UHR ESI-QTOF (positive ion):
m/
z calcd. for [M + Na]
+ C
65H
76NaO
18 1167.4924, found: 1164.4922.
Methyl (2,3-di-O-benzyl-4,6-O-benzylidene-α-d-glucopyranosyl)-(1→4)-[2,3-di-O-acetyl-6-O-(2-naphthyl)methyl-α-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (30)
Reaction 1.: Compound
21 (420 mg, 0.493 mmol) was glycosylated with
29 [
66] (453 mg, 0.839 mmol, 1.7 equiv.) according to general method A. The crude product was purified by silica gel chromatography (65:35
n-hexane/EtOAc) to give
30 (120 mg, 25%) as a colourless syrup.
Reaction 2.: Compound
21 (490 mg, 0.576 mmol) was glycosylated with
29 [
66] (529 mg, 0.979 mmol, 1.7 equiv.) according to general method A, but the temperature was allowed to warm up to 0 °C and mixture was stirred under Argon for 6 h. The crude product was purified by silica gel chromatography (65:35
n-hexane/EtOAc) to give
30 (246 mg, 33%) as a colourless syrup.
Reaction 3.: Compound
21 (668 mg, 0.785 mmol) was glycosylated with
29 [
66] (722 mg, 1.335 mmol, 1.7 equiv.) according to general method A, but the temperature was allowed to warm up to room temperature and the mixture was stirred under Argon for 48 h. The crude product was purified by silica gel chromatography (6:4
n-hexane/EtOAc) to give
30 (282 mg, 28%) as a colourless syrup.
Rf 0.50 (6:4
n-hexane/EtOAc);
+ 64.2 (
c 0.24, CHCl
3);
1H NMR (700 MHz, CDCl
3)
δ = 7.79–7.17 (m, 37H, arom.), 5.49 (s, 1H, H
ac), 5.44 (dd,
J = 3.1 Hz,
J = 8.5 Hz, 1H, H-3′), 5.41 (d,
J = 2.1 Hz, 1H, H-1′), 5.33 (t,
J = 2.8 Hz, 1H, H-2′), 5.18 (d,
J = 3.7 Hz, 1H, H-1″), 5.04–4.41 (m, 13H, H-1, NAP-C
H2, 5 × Bn-C
H2), 4.31 (t,
J = 9.0 Hz, 1H, H-4′), 4.04 (t,
J = 4.9 Hz,
J = 10.2 Hz, 1H, H-6a″), 3.98 (t,
J = 9.1 Hz, 1H, H-3), 3.93 (t,
J = 9.4 Hz, 1H, H-3″), 3.90 (d,
J = 9.6 Hz, 1H, H-5′), 3.86 (t,
J = 9.4 Hz, 1H, H-4), 3.82–3.78 (m, 3H, H-5, H-5″, H-6′a), 3.71 (dd,
J = 4.3 Hz,
J = 10.6 Hz, 1H, H-6a), 3.67 (d,
J = 10.8 Hz, 1H, H-6b), 3.54–3.50 (m, 3H, H-2, H-4″, H-6′b), 3.48–3.45 (m, 2H, H-2″, H-6″b), 3.39 (s, 3H, C-1-OC
H3), 1.95 (s, 3H, Ac-C
H3), 1.87 (s, 3H, Ac-C
H3) ppm;
13C NMR (176 MHz, CDCl
3)
δ = 169.9, 169.7 (2C, 2 × C
q Ac), 138.8, 138.7, 138.3, 138.1, 138.0, 137.6, 135.8, 133.4, 133.0 (9C, C
q arom.), 129.0–125.9 (37C, arom.), 101.3 (1C, C
ac), 99.0 (1C, C-1′), 97.9 (1C, C-1), 97.7 (1C, C-1″), 82.2 (1C, C-4″), 81.7 (1C, C-3), 80.3 (1C, C-2), 79.4 (1C, C-2″), 78.5 (1C, C-3″), 75.9 (1C, C-4), 75.4, 75.3, 73.7, 73.4, 73.3 (6C, 5 × Bn-
CH
2, NAP-
CH
2), 71.9 (1C, C-5′), 71.7 (1C, C-3′), 70.6 (1C, C-4′), 70.3 (1C, C-2′), 69.5 (1C, C-5), 69.2 (1C, C-6), 69.0 (1C, C-6″), 68.7 (1C, C-6′), 63.5 (1C, C-5″), 55.4 (1C, C-1-O
CH
3), 21.1, 20.9 (2C, 2 × Ac-
CH
3) ppm; UHR ESI-QTOF (positive ion):
m/
z calcd. for [M + Na]
+ C
76H
80NaO
18 1303.5237, found: 1303.5271.
Methyl (4-O-acetyl-2,3,6-tri-O-benzyl-α-d-glucopyranosyl)-(1→4)-[2,3-di-O-acetyl-6-O-(2-naphthyl)methyl-α-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (32)
Disaccharide acceptor
21 (2.000 g, 2.350 mmol) was glycosylated with
31 [
73] (2.061 g, 3.525 mmol, 1.5 equiv.) according to general method A. The crude product was purified by silica gel chromatography (6:4
n-hexane/acetone) to give
32 (2.70 g, 86%) as a colourless syrup.
Rf 0.48 (6:4
n-hexane/acetone);
+ 62.9 (
c 0.27, CHCl
3);
1H NMR (500 MHz, CDCl
3)
δ = 7.80–7.09 (m, 37H, arom.), 5.49 (dd,
J = 3.2 Hz,
J = 9.0 Hz, 1H, H-3′), 5.40 (d,
J = 2.0 Hz, 1H, H-1′), 5.34–5.33 (m, 1H, H-2′), 5.18 (d,
J = 3.5 Hz, 1H, H-1″), 5.05 (d,
J = 11.1 Hz, 1H, Bn-C
H2a), 4.99 (t,
J = 9.8 Hz, 1H, H-4″), 4.80–4.41 (m, 12H, H-1, NAP-C
H2, 4 × Bn-C
H2, Bn-C
H2b), 4.31–4.27 (m, 2H, H-4′, Bn-C
H2a), 4.11 (d,
J = 12.0 Hz, 1H, Bn-C
H2b), 3.99 (t,
J = 9.1 Hz, 1H, H-3), 3.96–3.90 (m, 2H, H-5′, H-6′a), 3.88–3.84 (m, 1H, H-4), 3.81–3.78 (m, 3H, H-3″, H-5, H-5″), 3.73–3.69 (m, 1H, H-6a), 3.71–3.69 (m, 1H, H-6b), 3.63–3.61 (m, 1H, H-6′b), 3.53 (dd,
J = 3.4 Hz,
J = 9.6 Hz, 1H, H-2), 3.49 (dd,
J = 3.5 Hz,
J = 9.8 Hz, 1H, H-2″), 3.39 (s, 3H, C-1-OC
H3), 3.18 (dd,
J = 2.4 Hz,
J = 10.6 Hz, 1H, H-6″b), 3.14 (dd,
J = 4.4 Hz,
J = 10.7 Hz, 1H, H-6″b), 1.98, 1.85, 1.73 (3 × s, 9H, 3 × Ac-C
H3) ppm;
13C NMR (125 MHz, CDCl
3)
δ = 170.0, 169.7 (3C, 3 × C
q Ac), 138.6, 138.3, 138.0, 137.8, 135.9, 133.3, 133.0 (9C, C
q arom.), 128.5–125.9 (37C, arom.), 99.1 (1C, C-1′), 97.9 (1C, C-1), 97.4 (1C, C-1″), 81.6 (1C, C-3), 80.2 (1C, C-2), 80.0 (1C, C-2″), 78.9 (1C, C-3″), 76.2 (1C, C-4), 75.3, 73.6, 73.5, 73.4, 73.3 (7C, 6 × Bn-
CH
2, NAP-
CH
2), 72.4 (1C, C-5′), 71.6 (1C, C-4′), 71.3 (1C, C-3′), 70.4 (1C, C-2′), 70.3 (1C, C-4″), 69.6 (2C, C-5, C-5″), 69.2 (1C, C-6), 69.0 (1C, C-6′), 68.6 (1C, C-6″), 55.4 (1C, C-1-O
CH
3), 21.1, 20.8 (3C, 3 × Ac-
CH
3) ppm; UHR ESI-QTOF (positive ion):
m/
z calcd. for [M + 2Na]
2+ C
78H
84Na
2O
19 685.2696, found: 685.2695.
Methyl (6-O-benzyl-2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-(2,3-di-O-acetyl-β-d-mannopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (34)
Compound 28 (410 mg, 0.358 mmol) was converted to 34 by general method D. The crude product was purified by silica gel chromatography (6:4 n-hexane/acetone) to produce compound 34 (260 mg, 72%) as a white foam. Rf 0.50 (6:4 n-hexane/acetone); + 79.0 (c 0.10, CHCl3); 1H NMR (700 MHz, CDCl3) δ = 7.33–7.22 (m, 20H, arom.), 5.38 (dd, J = 3.2 Hz, J = 9.1 Hz, 1H, H-3′), 5.34 (d, J = 1.8 Hz, 1H, H-1′), 5.26 (t, J = 2.4 Hz, 1H, H-2′), 5.23 (d, J = 4.0 Hz, 1H, H-1″), 5.03 (d, J = 11.1 Hz, 1H, Bn-CH2a), 4.71–4.69 (m, 2H, Bn-CH2a, Bn-CH2b), 4.61–4.51 (m, 6H, H-1, Bn-CH2b, 2 × Bn-CH2), 4.12 (t, J = 9.3 Hz, 1H, H-4′), 3.96 (t, J = 9.2 Hz, 1H, H-3), 3.82 (t, J = 8.9 Hz, 1H, H-4), 3.74–3.72 (m, 2H, H-5, H-5′), 3.71–3.68 (m, 1H, H-6′a), 3.66–3.62 (m, 4H, H-5″, H-6a,b, H-6″a), 3.60–3.58 (m, 5H, OCH3, H-6′b, H-6″b), 3.51 (dd, J = 3.4 Hz, J = 9.6 Hz, 1H, H-2), 3.45 (2 × s, 6H, 2 × OCH3), 3.44 (t, J = 9.3 Hz, 1H, H-3″), 3.39 (s, 3H, C-1-OCH3), 3.13 (dd, J = 4.0 Hz, J = 9.8 Hz, 1H, H-2″), 3.08 (t, J = 9.5 Hz, 1H, H-4″), 2.65–2.64 (m, 1H, H-6′-OH), 1.96 (s, 3H, Ac-CH3), 1.89 (s, 3H, Ac-CH3) ppm; 13C NMR (176 MHz, CDCl3) δ = 169.6, 169.5 (2C, 2 × Cq Ac), 138.5, 138.1, 138.0, 137.5 (4C, Cq arom.), 128.5–127.2 (20C, arom.), 99.1 (1C, C-1′), 97.7 (1C, C-1), 97.6 (1C, C-1″), 83.6 (1C, C-3″), 81.6 (1C, C-3), 81.2 (1C, C-2″), 80.1 (1C, C-2), 79.9 (1C, C-4″), 76.0 (1C, C-4), 75.1, 73.6, 73.5, 73.2 (4C, 4 × Bn-CH2), 72.2 (1C, C-5′), 72.0 (1C, C-3′), 71.3 (1C, C-5″), 70.1 (2C, C-2′, C-4′), 69.5 (1C, C-5), 68.8, 69.7 (2C, C-6, C-6″), 61.1 (1C, C-6′), 60.7, 60.5, 59.5 (3C, 3 × OCH3), 55.3 (1C, C-1-OCH3), 20.9, 20.7 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C54H68NaO18 525.2095, found: 525.2095.
Methyl (6-O-benzyl-2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-(sodium 2,3-di-O-acetyl-β-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (35)
Compound 34 (260 mg, 0.259 mmol) was converted to 35 according to general method E. The crude product was purified by silica gel chromatography (95:5 CH2Cl2/MeOH) to produce compound 35 (209 mg, 78%) as a white foam. Rf 0.38 (95:5 CH2Cl2/MeOH); + 1.43 (c 0.15, CHCl3); 1H NMR (700 MHz, CD3OD) δ = 7.33–7.22 (m, 20H, arom.), 5.46 (d, J = 3.4 Hz, 1H, H-1′), 5.36 (dd, J = 3.2 Hz, J = 7.1 Hz, 1H, H-3′), 5.23 (t, J = 3.4 Hz, 1H, H-2′), 5.19 (d, J = 3.8 Hz, 1H, H-1″), 5.01 (d, J = 10.9 Hz, 1H, Bn-CH2a), 4.73–4.47 (m, 8H, H-1, Bn-CH2a, 3 × Bn-CH2), 4.34–4.30 (m, 2H, H-4′, H-5′), 3.95 (t, J = 9.2 Hz, 1H, H-3), 3.90 (t, J = 9.2 Hz, 1H, H-4), 3.85 (dd, J = 4.1 Hz, J = 12.0 Hz, 1H, H-6″a), 3.75–3.72 (m, 3H, H-5, H-5″, H-6″b), 3.68 (dd, J = 1.7 Hz, J = 10.7 Hz, 1H, H-6a), 3.63 (dd, J = 4.0 Hz, J = 10.5 Hz, 1H, H-6b), 3.58 (s, 3H, OCH3), 3.50 (dd, J = 3.5 Hz, J = 9.5 Hz, 1H, H-2), 3.46–3.44 (m, 4H, H-3″, OCH3), 3.43 (s, 3H, OCH3), 3.38 (s, 3H, C-1-OCH3), 3.17 (d, J = 9.5 Hz, 1H, H-4″), 3.14 (dd, J = 3.9 Hz, J = 9.8 Hz, 1H, H-2″), 1.93 (s, 3H, Ac-CH3), 1.89 (s, 3H, Ac-CH3) ppm; 13C NMR (176 MHz, CD3OD) δ = 169.6, 169.5 (3C, COONa, 2 × Cq Ac), 138.7, 138.1, 137.9, 137.8 (4C, Cq arom.), 128.5–127.4 (20C, arom.), 99.1 (1C, C-1′), 97.9 (1C, C-1), 97.4 (1C, C-1″), 83.2 (1C, C-3″), 81.4 (2C, C-2″, C-3), 80.2 (1C, C-2), 79.6 (1C, C-4″), 76.3 (1C, C-4), 75.2, 73.9, 73.7, 73.3 (4C, 4 × Bn-CH2), 72.6 (2C, C-4′, C-5′), 71.0 (1C, C-5″), 70.5 (1C, C-3′), 69.6 (1C, C-5), 69.5 (1C, C-2′), 68.9 (1C, C-6″), 68.7 (1C, C-6), 60.8, 60.5, 59.3 (3C, 3 × OCH3), 55.4 (1C, C-1-OCH3), 20.9, 20.8 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C54H65NaO19 1041.4091, found: 1041.4090.
Methyl (6-O-benzyl-2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-[2,3-di-O-acetyl-α-d-mannopyranosyl]-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (36)
Compound 27 (1.20 g, 1.047 mmol) was converted to 36 by general method D. The crude product was purified by silica gel chromatography (6:4 n-hexane/acetone) to produce compound 36 (723 mg, 69%) as a white foam. Rf 0.41 (6:4 n-hexane/acetone); + 81.9 (c 0.26, CHCl3); 1H NMR (500 MHz, CDCl3) δ = 7.33–7.21 (m, 20H, arom.), 5.38 (dd, J = 3.3 Hz, J = 9.1 Hz, 1H, H-3′), 5.33 (d, J = 1.9 Hz, 1H, H-1′), 5.25 (t, J = 2.6 Hz, 1H, H-2′), 5.23 (d, J = 4.0 Hz, 1H, H-1″), 5.03 (d, J = 11.1 Hz, 1H, Bn-CH2a), 4.72–4.50 (m, 8H, H-1, Bn-CH2b, 3 × Bn-CH2), 4.12 (t, J = 9.3 Hz, 1H, H-4′), 3.96 (t, J = 9.1 Hz, 1H, H-3), 3.82 (t, J = 8.9 Hz, 1H, H-4), 3.75–3.72 (m, 2H, H-5, H-5′), 3.67–3.64 (m, 4H, H-5″, H-6a, H-6′a, H-6″a), 3.60 (s, 3H, OCH3), 3.59–3.57 (m, 3H, H-6b, H-6′b, H-6″b), 3.51 (dd, J = 3.5 Hz, J = 9.6 Hz, 1H, H-2), 3.45 (2 × s, 6H, 2 × OCH3), 3.43 (t, J = 9.4 Hz, 1H, H-3″), 3.39 (s, 3H, C-1-OCH3), 3.13 (dd, J = 4.0 Hz, J = 9.8 Hz, 1H, H-2″), 3.08 (t, J = 9.4 Hz, 1H, H-4″), 2.63 (t, J = 6.3 Hz, 1H, H-6′-OH), 1.96 (s, 3H, Ac-CH3), 1.89 (s, 3H, Ac-CH3) ppm; 13C NMR (125 MHz, CDCl3) δ = 169.6, 169.5 (2C, 2 × Cq Ac), 138.6, 138.1, 138.0, 137.6 (4C, Cq arom.), 128.5–127.2 (20C, arom.), 99.1 (1C, C-1′), 97.8 (1C, C-1), 97.6 (1C, C-1″), 83.6 (1C, C-3″), 81.6 (1C, C-3), 81.3 (1C, C-2″), 80.1 (1C, C-2), 79.9 (1C, C-4″), 76.0 (1C, C-4), 75.1, 73.6, 73.5, 73.2 (4C, 4 × Bn-CH2), 72.2 (1C, C-5′), 72.0 (1C, C-3′), 71.4 (1C, C-5″), 70.1 (2C, C-2′, C-4′), 69.6 (1C, C-5), 68.8 (2C, C-6, C-6″), 61.2 (1C, C-6′), 60.7, 60.5, 59.6 (3C, 3 × OCH3), 55.3 (1C, C-1-OCH3), 20.9, 20.7 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C54H68Na2O18 525.2095, found: 525.2095.
Methyl (6-O-benzyl-2,3,4-tri-O-methyl-α-d-glucopyranosyl)-(1→4)-(sodium 2,3-di-O-acetyl-α-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (37)
Compound 36 (653 mg, 0.649 mmol) was converted to 37 according to general method E. The crude product was purified by silica gel chromatography (95:5 CH2Cl2/MeOH) to produce compound 37 (527 mg, 78%) as a white foam. Rf 0.83 (1:1 CH2Cl2/MeOH); + 61.4 (c 0.28, CHCl3); 1H NMR (700 MHz, CDCl3) δ = 7.33–7.22 (m, 20H, arom.), 5.45 (d, J = 3.0 Hz, 1H, H-1′), 5.36 (dd, J = 3.1 Hz, J = 7.4 Hz, 1H, H-3′), 5.24 (t, J = 3.3 Hz, 1H, H-2′), 5.19 (d, J = 3.7 Hz, 1H, H-1″), 5.01 (d, J = 11.0 Hz, 1H, Bn-CH2a), 4.72–4.46 (m, 8H, H-1, Bn-CH2a, 3 × Bn-CH2), 4.33 (t, J = 8.1 Hz, 1H, H-4′), 4.31 (t, J = 7.8 Hz, 1H, H-5′), 3.95 (t, J = 9.2 Hz, 1H, H-3), 3.90 (t, J = 9.4 Hz, 1H, H-4), 3.84 (dd, J = 2.8 Hz, J = 11.1 Hz, 1H, H-6a), 3.74–3.70 (m, 3H, H-5, H-5″, H-6b), 3.68–3.67 (m, 1H, H-6″a), 3.63 (dd, J = 4.0 Hz, J = 10.6 Hz, 1H, H-6″b), 3.58 (s, 3H, OCH3), 3.50 (dd, J = 3.4 Hz, J = 9.5 Hz, 1H, H-2), 3.46–3.44 (m, 4H, H-3″, OCH3), 3.42 (s, 3H, OCH3), 3.38 (s, 3H, C-1-OCH3), 3.17 (d, J = 10.2 Hz, 1H, H-4″), 3.13 (dd, J = 3.8 Hz, J = 9.8 Hz, 1H, H-2″), 1.93 (s, 3H, Ac-CH3), 1.88 (s, 3H, Ac-CH3) ppm; 13C NMR (176 MHz, CDCl3) δ = 169.6 (3C, COONa, 2 × Cq Ac), 138.6, 138.0, 137.8 (4C, Cq arom.), 128.6–127.4 (20C, arom.), 99.2 (1C, C-1′), 97.9 (1C, C-1), 97.4 (1C, C-1″), 83.2 (1C, C-3″), 81.5 (2C, C-2″, C-3), 80.2 (1C, C-2), 79.6 (1C, C-4″), 76.3 (1C, C-4), 75.2, 73.9, 73.7, 73.3 (4C, 4 × Bn-CH2), 72.6 (2C, C-4′, C-5′), 71.0 (1C, C-5″), 70.6 (1C, C-3′), 69.6 (1C, C-5), 69.5 (1C, C-2′), 68.9 (1C, C-6″), 68.7 (1C, C-6), 60.8, 60.5, 59.3 (3C, 3 × OCH3), 55.4 (1C, C-1-OCH3), 20.9, 20.7 (2C, 2 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C54H65NaO19 1041.4091, found: 1041.4095.
Methyl (4-O-acetyl-2,3,6-tri-O-benzyl-α-d-glucopyranosyl)-(1→4)-(2,3-di-O-acetyl-α-d-mannopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (38)
Compound 32 (2.02 g, 1.527 mmol) was converted to 38 by general method D. The crude product was purified by silica gel chromatography (6:4 n-hexane/acetone) to produce compound 38 (985 mg, 54%) as a white foam. Rf 0.64 (1:1 n-hexane/acetone); + 68.8 (c 0.49, CHCl3); 1H NMR (700 MHz, CDCl3) δ = 7.32–7.22 (m, 30H, arom.), 5.42 (dd, J = 3.2 Hz, J = 8.5 Hz, 1H, H-3′), 5.37 (d, J = 2.5 Hz, 1H, H-1′), 5.31 (t, J = 3.0 Hz, 1H, H-2′), 5.32 (d, J = 3.0 Hz, 1H, H-1″), 5.04 (d, J = 11.0 Hz, 1H, Bn-CH2a), 4.97 (t, J = 10.1 Hz, 1H, H-4″), 4.80–4.64 (m, 5H, Bn-CH2a, 2 × Bn-CH2b, Bn-CH2), 4.61 (d, J = 3.6 Hz, 1H, H-1), 4.60–4.46 (m, 6H, 3 × Bn-CH2), 4.15 (t, J = 9.0 Hz, 1H, H-4′), 3.98 (t, J = 9.1 Hz, 1H, H-3), 3.85 (t, J = 9.5 Hz, 1H, H-4), 3.84–3.80 (m, 3H, H-3″, H-5′, H-5″), 3.79–3.75 (m, 3H, H-5, H-6a, H-6′a), 3.68–3.66 (m, 2H, H-6b, H-6′b), 3.57 (dd, J = 3.8 Hz, J = 9.7 Hz, 1H, H-2″), 3.53 (dd, J = 3.4 Hz, J = 9.7 Hz, 1H, H-2), 3.44 (dd, J = 2.4 Hz, J = 10.5 Hz, 1H, H-6″a), 3.42–3.41 (m, 1H, H-6″b), 3.40 (s, 3H, C-1-OCH3), 2.63 (t, J = 6.6 Hz, 1H, H-6′-OH), 1.93, 1.85, 1.82 (3 × s, 9H, 3 × Ac-CH3) ppm; 13C NMR (176 MHz, CDCl3) δ = 169.9, 169.7, 169.6 (3C, 3 × Cq Ac), 138.6, 138.5, 138.3, 138.1, 137.7, 137.5 (6C, Cq arom.), 128.6–127.4 (30C, arom.), 99.1 (1C, C-1′), 97.9 (1C, C-1), 97.3 (1C, C-1″), 81.7 (1C, C-3), 80.3 (1C, C-2), 79.6 (1C, C-2″), 79.0 (1C, C-3″), 75.8 (1C, C-4), 75.4, 75.2, 73.7, 73.6, 73.3 (6C, 6 × Bn-CH2), 72.5 (1C, C-5′), 71.9 (1C, C-3′), 70.5 (1C, C-4′), 70.3 (1C, C-4″), 70.2 (2C, C-2′, C-5″), 69.8 (1C, C-5), 68.9 (1C, C-6), 68.7 (1C, C-6″), 61.6 (1C, C-6′), 55.5 (1C, C-1-OCH3), 21.1, 20.9, 20.8 (3C, 3 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + 2Na]2+ C67H76Na2O19 615.2383, found: 615.2385.
Methyl (4-O-aceyl-2,3,6-tri-O-benzyl-α-d-glucopyranosyl)-(1→4)-(sodium 2,3-di-O-acetyl-α-d-mannopyranosyl-uronate)-(1→4)-2,3,6-tri-O-benzyl-α-d-glucopyranoside (39)
Compound 38 (940 mg, 0.793 mmol) was converted to 39 according to general method E, using CH3CN instead of CH2Cl2 as a solvent. The crude product was purified by silica gel chromatography (95:5 CH2Cl2/MeOH) to produce compound 39 (735 mg, 76%) as a white foam. Rf 0.36 (4:6 n-hexane/acetone); + 13.6 (c 0.14, CHCl3); 1H NMR (700 MHz, CD3OD) δ = 7.37–7.19 (m, 30H, arom.), 5.73 (d, J = 6.0 Hz, 1H, H-1′), 5.38 (dd, J = 3.2 Hz, J = 5.6 Hz, 1H, H-3′), 5.23 (dd, J = 3.1 Hz, J = 6.3 Hz, 1H, H-2′), 5.14 (d, J = 3.5 Hz, 1H, H-1″), 4.98 (t, J = 9.8 Hz, 1H, H-4″), 4.91–4.74 (m, 6H, 3 × Bn-CH2), 4.71 (d, J = 3.4 Hz, 1H, H-1), 4.65 (d, J = 4.0 Hz, 1H, H-5′), 4.61–4.37 (m, 6H, 3 × Bn-CH2), 4.34 (t, J = 4.6 Hz, 1H, H-4′), 3.97 (ddd, J = 2.7 Hz, J = 4.6 Hz, J = 10.1 Hz, 1H, H-5″), 3.94 (t, J = 9.2 Hz, 1H, H-4), 3.91–3.86 (m, 3H, H-3, H-3″, H-6a), 3.74 (ddd, J = 1.6 Hz, J = 5.5 Hz, J = 9.8 Hz, 1H, H-5), 3.69 (dd, J = 5.5 Hz, J = 10.9 Hz, 1H, H-6b), 3.56 (dd, J = 3.6 Hz, J = 9.8 Hz, 1H, H-2″), 3.54 (dd, J = 3.5 Hz, J = 9.6 Hz, 1H, H-2), 3.46 (dd, J = 2.5 Hz, J = 10.8 Hz, 1H, H-6″a), 3.41 (dd, J = 4.8 Hz, J = 10.8 Hz, 1H, H-6″b), 3.36 (s, 3H, C-1-OCH3), 1.96, 1.79, 1.73 (3 × s, 9H, 3 × Ac-CH3) ppm; 13C NMR (176 MHz, CD3OD) δ = 171.5, 171.3, 171.2 (4C, COONa, 3 × Cq Ac), 140.2, 139.8, 139.7, 139.6, 139.5, 139.3 (6C, Cq arom.), 129.5–128.2 (30C, arom.), 99.4 (1C, C-1″), 98.8 (1C, C-1), 97.9 (1C, C-1′), 82.6 (1C, C-3), 81.5 (1C, C-2), 81.0 (1C, C-2″), 79.7 (1C, C-3″), 76.6 (1C, C-4), 76.1, 75.8 (2C, 2 × Bn-CH2), 75.7 (1C, C-4′), 75.1 (1C, C-5′), 74.6, 74.4, 74.1, 73.9 (4C, 4 × Bn-CH2), 71.5 (1C, C-4″), 71.4 (1C, C-3′), 71.0 (2C, C-5, C-5″), 70.9 (1C, C-6), 70.2 (1C, C-2′), 70.0 (1C, C-6″), 55.6 (1C, C-1-OCH3), 21.0, 20.8 (3C, 3 × Ac-CH3) ppm; UHR ESI-QTOF (positive ion): m/z calcd. for [M + H]+ C67H74NaO20 1221.4666, found: 1221.4634.