Paper
Organic & Biomolecular Chemistry
by flash silica gel column chromatography (hexane : AcOEt = quenched with saturated aq. NaHCO3. The mixture was
4 : 1) to give 17 (3.7 g, 4.7 mmol, 70% yield, α : β = 52 : 48). extracted with CH2Cl2. The organic layer was washed with
[α]2D7 −22.1 (c 0.10, MeOH); 1H-NMR (400 MHz, CDCl3) brine and dried over Na2SO4. After concentration, 19 was used
δ 8.05–7.32 (m, 15H; Bz), 6.20 (d, J = 3.6 Hz, 0.5H; H-1α), 5.66 without purification for the next step.
(t, J = 6.9 Hz, 0.5H; H-3′α), 5.62 (t, J = 6.0 Hz, 0.5H; H-3′β), 5.60
2,3,4-Tri-O-benzoyl-β-D-xylopyranosyl-(1 → 6)-2,3,4-tri-O-
(d, J = 7.8 Hz, 0.5H; H-1β), 5.34 (t, J = 9.9 Hz, 0.5H; H-3α), 5.27 acetyl-D-glucopyranosyl fluoride (20). To a solution of 18
(dd, J = 6.9 Hz, 4.8 Hz, 0.5H; H-2′α), 5.24 (dd, J = 6.0 Hz, (20 mg, 27 μmol) in CH2Cl2 (0.39 mL) was added (diethyl-
4.8 Hz, 0.5H; H-2′β), 5.22–5.20 (m, 0.5H; H-4′α), 5.19–5.17 (m, amino)sulfur trifluoride (5.0 μL, 38 μmol) at −30 °C and the
0.5H; H-4′β), 5.14 (t, J = 9.6 Hz, 0.5H; H-3β), 5.01–4.97 (m, 1H; reaction mixture was allowed to warm to room temperature.
H-4α, H-2β), 4.86 (dd, J = 9.9 Hz, 3.6 Hz, 0.5H; H-2α), 4.82 (d, After stirring for 1 h, the reaction mixture was cooled to
J = 4.8 Hz, 0.5H; H-1′α), 4.79 (d, J = 4.8 Hz, 0.5H; H-1′β), 4.39 −30 °C, and quenched with MeOH. The solvent was concen-
(dd, 12.0 Hz, 3.6 Hz, 0.5H; H-5′aβ), 4.37 (dd, J = 12.3 Hz, trated in vacuo, and taken up in CHCl3. The organic layer was
4.2 Hz, 0.5H; H-5′aα), 4.04–4.02 (m, 0.5H; H-5α), 3.90 (dd, J = washed with H2O, dried over Na2SO4, filtered and evaporated
11.7 Hz, 1.8 Hz, 1H; H-6aα, H-6aβ), 3.78–3.74 (m, 0.5H; H-4β), in vacuo. The residue was purified by flash silica gel column
3.68 (dd, J = 12.0 Hz, 6.6 Hz, 0.5H; H-5′bβ), 3.66 (dd, J = chromatography (hexane/AcOEt = 3 : 2) to give 20 (16 mg,
12.3 Hz, 6.6 Hz, 0.5H; H-5′bα), 3.61 (dd, J = 11.7 Hz, 4.8 Hz, 21 µmol, 79% yield, α : β = 28 : 72). [α]2D8 −50.4 (c 0.10, MeOH);
0.5H; H-6bβ), 3.61–3.57 (m, 1H; H-6bα, H-5β), 2.15–1.96 1H-NMR (600 MHz, CDCl3) δ 8.02–7.33 (m, 15H), 5.75–5.72 (m,
(m, 12H; Ac); 13C-NMR (100 MHz, CDCl3) δ 170.0, 169.9, 169.4, 1H; α × 1, β × 1), 5.67 (dd, J = 53.4 Hz, 2.7 Hz, 0.3H; H-1α), 5.44
169.1, 169.0, 168.6, 168.5, 168.5, 165.5, 165.3, 165.0, 165.0, (t, J = 9.6 Hz, 0.3H; α), 5.37–5.34 (m, 1H; α × 1, β × 1), 5.30–5.27
164.9, 133.2, 133.1, 129.7, 129.1, 129.0, 128.9, 128.3, 128.2, (m, 1H; α × 1, β × 1), 5.20–5.05 (m, 2.4H; α × 1, β × 3), 4.89 (d,
128.2, 128.1, 99.7, 99.3, 91.6, 88.7, 73.7, 72.6, 70.8, 70.1, 69.6, J = 6.0 Hz, 0.7H; H-1′β), 4.88 (d, J = 4.8 Hz, 0.3H; H-1′α), 4.78
69.4, 69.1, 69.0, 68.8, 68.6, 68.2, 68.1, 68.0, 66.9, 66.9, 60.6, (ddd, J = 24.0 Hz, 10.2 Hz, 2.7 Hz, 0.3H; H-2α), 4.46–4.43
60.2, 60.1, 20.8, 20.7, 20.5, 20.5, 20.4, 20.2; IR (ATR) 1727, (m, 1H; α × 1, β × 1), 4.18–4.15 (m, 0.3H; α), 4.01–3.98 (m, 1H;
1369, 1250, 1217, 1070, 712 cm−1; ESI-HRMS m/z calcd for α × 1, β × 1), 3.83–3.80 (m, 0.7H; β), 3.76–3.66 (m, 2H; α × 2,
C40H40NaO17 815.2163, found 815.2120 [M + Na]+.
β × 2), 2.09 (s, 0.9H; α), 2.06 (s, 2.1H; β), 2.03 (s, 2.1H; β), 2.00
2,3,4-Tri-O-benzoyl-β-D-xylopyranosyl-(1 → 6)-2,3,4-tri-O- (s, 0.9H; α), 1.98 (s, 2.1H; β), 1.98 (s, 0.9H; α); 13C-NMR
acetyl-D-glucopyranoside (18). To a solution of 17 (1.27 g, (150 MHz, CDCl3) δ 170.0, 169.9, 169.9, 169.2, 169.2, 169.1,
1.6 mmol) in THF (11 mL) was added benzylamine (0.35 mL, 133.4, 133.3, 133.2, 129.9, 129.9, 129.8, 129.2, 129.2, 129.1,
3.2 mmol). After stirring at room temperature for 24 h, the 128.4, 128.4, 128.4, 128.3, 128.3, 106.3 (d, J = 218.0 Hz), 103.6
reaction mixture was diluted with AcOEt and extracted with (d, J = 227.7 Hz), 100.3, 99.9, 73.3 (d, J = 3.2 Hz), 71.7 (d, J =
AcOEt. The combined organic layer was dried over Na2SO4 and 8.7 Hz), 71.2, 71.1, 70.8 (d, J = 4.4 Hz), 70.3, 70.2, 69.7 (d, J =
evaporated in vacuo. The residue was purified by flash silica 4.4 Hz), 69.5 (d, J = 4.4 Hz), 69.3, 68.8, 68.7, 67.8, 67.7, 67.6,
gel column chromatography (hexane : AcOEt = 1 : 1) to give 18 66.8, 61.0, 60.8, 20.6, 20.5, 20.5, 20.5, 20.5, 20.5; IR (ATR)
(1.00 g, 1.3 mmol, 83% yield, α : β = 71 : 29). [α]2D7 +20.9 (c 0.10, 1725, 1452, 1369, 1247, 1216, 1095, 1069, 1039, 710 cm−1
;
1
MeOH); H-NMR (600 MHz, CDCl3) δ 8.02–7.34 (m, 15H; Bz), ESI-HRMS m/z calcd for C38H37NaO15 775.2014, found
5.75 (t, J = 6.6 Hz, 0.7H; α), 5.73 (t, J = 6.6 Hz, 0.3H; β), 5.46 (t, 775.1952 [M + Na]+.
J = 10.8 Hz, 0.7H; α), 5.35–5.28 (m, 2H; α × 2, β × 2), 5.24 (d, J =
6-O-(2,3,4-Tri-O-benzoyl-D-xylopyranosyl)-2,3,4-tri-O-actyl-
3.6 Hz, 0.7H; H-1α), 5.17 (t, J = 9.6 Hz, 0.3H; β), 4.96–4.88 (m, glucopyranosyl trichloroacetimidate (21). To a solution of 18
2H; α × 2, β × 2), 4.82–4.80 (m, 0.3H; β), 4.75 (dd, J = 9.6 Hz, (31 mg, 41 μmol) in CH2Cl2 (0.72 mL) were added trichloro-
3.0 Hz, 0.7H; α), 4.62 (d, J = 8.4 Hz, 0.3H; H-1β), 4.46–4.42 acetonitrile (118 mg, 0.82 mmol) and DBU (6.1 μL, 41 μmol) at
(m, 1H; α × 1, β × 1), 4.24–4.22 (m, 0.7H; α), 3.93–3.88 (m, 1H; 0 °C. After stirring at this temperature for 24 h, the reaction
α × 1, β × 1), 3.75–3.63 (m, 2.3H; α × 2, β × 3), 2.05–1.97 (m, 9H; mixture was diluted with CH2Cl2 and evaporated in vacuo. The
Ac); 13C-NMR (150 MHz, CDCl3) δ 170.4, 170.2, 170.1, 170.0, residue was purified by flash silica gel column chromato-
169.7, 169.5, 165.6, 165.5, 165.4, 165.3, 165.3, 165.3, 133.4, graphy (hexane : AcOEt = 2 : 1) to give 21 (32.5 mg, 36 µmol,
133.4, 129.9, 129.9, 129.8, 129.2, 129.2, 129.1, 129.1, 128.4, 89% yield, α only). [α]2D6 +17.7 (c 0.10, MeOH); 1H-NMR
128.4, 128.4, 100.4, 100.1, 95.3, 89.8, 73.6, 73.0, 72.3, 71.0, (400 MHz, CDCl3) δ 8.52 (s, 1H), 8.02–7.31 (m, 15H), 6.51 (d,
70.3, 70.0, 69.8, 69.8, 69.6, 69.0, 69.0, 68.8, 68.7, 68.6, 68.0, J = 3.8 Hz, 1H), 5.70 (dd, J = 6.6 Hz, 6.2 Hz, 1H), 5.51 (dd, J =
67.7, 61.0, 60.8, 20.7, 20.7, 20.6, 20.6, 20.6, 20.6; IR (ATR) 3772, 10.0 Hz, 9.8 Hz, 1H), 5.33 (dd, J = 6.6 Hz, 4.8 Hz, 1H), 5.26 (m,
1733, 1602, 1452, 1368, 1316, 1262, 1178, 1109, 1071, 1043, 1H), 5.11 (t, J = 9.8 Hz, 1H), 4.95 (dd, J = 10.0 Hz, 3.8 Hz, 1H),
714 cm−1; ESI-HRMS m/z calcd for C38H38NaO16 773.2058, 4.87 (d, J = 4.8 Hz, 1H), 4.44 (dd, J = 11.6 Hz, 3.6 Hz, 1H), 4.19
found 773.2021 [M + Na]+.
(m, 1H), 3.98 (dd, J = 11.6 Hz, 1.6 Hz, 1H), 3.75–3.66 (m, 2H),
2,3,4-Tri-O-benzoyl-β-D-xylopyranosyl-(1 → 6)-2,3,4-tri-O- 2.04 (s, 3H), 2.02 (s, 3H), 1.98 (s, 3H); 13C-NMR (100 MHz,
acetyl-D-glucopyranosyl chloride (19). To a solution of 17 CDCl3) δ 170.0, 169.8, 169.3, 165.5, 165.2, 165.0, 160.6, 133.4,
(15 mg, 19 µmol) in CH2Cl2 was added thionyl chloride 133.3, 133.2, 129.9, 129.9, 129.8, 129.3, 129.2, 129.1, 128.4,
(5.5 μL, 76 μmol) and tin(IV) chloride (4.4 μL, 38 μmol). The 128.4, 128.3, 99.8, 92.8, 90.6, 71.2, 69.8, 69.6, 69.5, 68.8, 68.2,
reaction mixture was stirred for 1 h at room temperature and 67.0, 60.8, 20.7, 20.5, 20.4; IR (ATR) 1730, 1246, 1070,
Org. Biomol. Chem.
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