K. D. Randell et al. / Tetrahedron: Asymmetry 11 (2000) 207–222
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Compound 9α: 1H NMR (CD2Cl2): δ 8.20–7.10 (25H, m, aromatic), 5.67 (1H, dd, J1,2=1.8 Hz, H2B),
5.66–5.62 (3H, m, H3A, H1A, CHPh), 5.25 (1H, ddd, H5A), 5.21 (1H, d, H1B), 5.00 (1H, dd, J1,2=4.1,
J2,3=9.5 Hz, H2A), 4.89–4.53 (6H, CH2Ph), 4.79 (1H, d, J1,2=1.8 Hz, H1C), 4.34 (1H, dd, J2,3=3.7,
0
0
J3,4=9.3 Hz, H3B), 4.31 (1H, dd, J5,6=4.7, J6,6 =10.1 Hz, H6B), 4.25 (1H, dd, J5,6=3.9, J6,6 =12.1 Hz,
H6A), 4.12–4.01 (4H, m, H6A0, H2C, H5B, H4B), 3.93–3.84 (3H, m, H4C, H3C, H6B0), 3.78–3.71
(3H, m, H5C, H6C, H6C0), 3.50 (1H, dd, J3,4=7.4, J4,5=6.1 Hz, H4A), 3.37 (3H, OCH3), 2.0–1.46
(4s, 3H each, C(O)CH3). 13C NMR (CD2Cl2): δ 172.52–169.74 (4C, C(O)CH3), 165.53 (C(O)Ph),
139.06–125.61 (30C, aromatic), 102.00 (CHPh), 100.60 (C1B), 100.48 (C1C), 82.35 (C1A), 80.24
(C3C), 78.40 (C2A), 78.00 (C4B), 75.58 (C2C), 75.38–75.18 (2C, C4C, CH2Ph), 74.36 (C3A), 73.84
(C3B), 73.59 (CH2Ph), 72.80 (CH2Ph), 72.23 (C5C), 71.14 (C5A), 69.92 (C6C), 69.47 (C2B), 69.07
(C6B), 64.07 (C5B), 63.95 (C6A), 55.01 (-OCH3), 44.58 (C4A), 21.51–20.05 (4C, C(O)CH3).
Compound 9β: 1H NMR (CD2Cl2): δ 8.20–7.10 (25H, m, aromatic), 5.76 (1H, dd, J1,2=1.6, J2,3=3.7
Hz, H2B), 5.66–5.62 (1H, s, CHPh), 5.27 (1H, d, J1,2=2.7 Hz, H1A), 5.22 (1H, dd, J2,3=4.8 Hz, H2A),
0
5.20 (1H, d, H1B), 5.17 (1H, ddd, J5,6=4.0, J5,6 =9.3, J4,5=5.2 Hz, H5A), 5.12 (1H, dd, J3,4=7.5 Hz,
H3A), 4.89–4.53 (6H, CH2Ph), 4.79 (1H, d, J1,2=1.8 Hz, H1C), 4.47 (1H, dd, J3,4=9.6 Hz, H3B), 4.31
0
(1H, dd, J5,6=4.7, J6,6 =10.1 Hz, H6B), 4.15 (1H, dd, J4,5=9.4 Hz, H4B), 4.12–4.01 (3H, m, H6A,
H2C, H5B), 3.93–3.84 (4H, m, H3C, H4C, H6A0, H6B0), 3.78–3.71 (4H, m, H4A, H6C, H6C0, H5C),
3.37 (3H, s, OCH3), 2.00–1.84 (4s, 3H each, C(O)CH3). 13C NMR (CD2Cl2): δ 170.52–169.74 (4C,
C(O)CH3), 165.46 (C(O)Ph), 139.06–125.61 (30C, aromatic), 102.09 (CHPh), 100.60 (C1B), 100.18
(C1C), 87.64 (C1A), 82.76 (C2A), 80.41 (C4B), 80.10 (C3C), 77.43 (C3A), 75.43 (C2C), 75.38–75.18
(2C, C4C, CH2Ph), 73.56 (CH2Ph), 72.71 (CH2Ph), 72.16 (C5C), 71.77, 71.73 (C2B, C3B), 69.69 (C6C),
69.47 (C5A), 69.03 (C6B), 64.66 (C5B), 63.32 (C6A), 55.01 (-OCH3), 49.70 (C4A), 21.51–20.05 (4C,
C(O)CH3).
In another experiment, the methyl glycoside acceptor 8 (121 mg, 0.26 mmol) was glycosylated with
the thioglycoside donor 7 (238 mg, 0.31 mmol) following the general procedure, except that 1 equiv. of
NIS was used. The reaction time was 2.5 h at 0°C–rt. The trisaccharide 9 was obtained as a mixture of
compounds (α:β, 0.47:1). The mixture could not be purified by column chromatography.
The mixture of trisaccharides 9α and 9β was dissolved in 80% AcOH(aq) and stirred overnight at room
temperature. The reaction mixture was concentrated and co-concentrated with distilled toluene to remove
traces of AcOH. Compounds 10α and 10β were obtained as a clear glass (α:β, 1:1.3).
Compound 10α: 1H NMR (CD2Cl2): δ 8.10–7.10 (20H, m, aromatic), 5.62 (1H, dd, J2,3=9.3, J3,4=7.8
Hz, H3A), 5.57 (1H, dd, J1,2=1.8, J2,3=3.2 Hz, H2B), 5.49 (1H, d, J1,2=4.4 Hz, H1A), 5.18 (1H, m, H1B),
5.11 (1H, ddd, H5A), 5.07 (1H, dd, H2A), 4.90–4.54 (6H, CH2Ph), 4.79 (1H, d, J1,2=1.9 Hz, H1C), 4.18
0
0
(1H, dd, J5,6=3.9, J6,6 =12.0 Hz, H6A), 4.10–3.93 (4H, m, H6A , H2C, H3B, H4B*), 3.92–3.79 (6H,
m, H6C, H6C0, H6B, H6B0, H3C, H4C*), 3.78–3.67 (2H, m, H5C*, H5B*), 3.52 (1H, dd, J4,5=5.9 Hz,
H4A), 3.34 (3H, OCH3), 2.01–1.85 (4s, 3H each, C(O)CH3). 13C NMR (CD2Cl2): δ 171.18–170.13 (4C,
C(O)CH3), 165.54 (C(O)Ph), 139.04–127.88 (24C, aromatic), 100.04 (C1C), 99.50 (C1B), 82.34 (C1A),
80.16 (C3C), 78.40 (C2A), 77.29 (C2C), 75.44–75.21 (2C, C3B, CH2Ph), 75.11–66.75 (4C, C4C, C4B,
C5B, C5C), 74.25 (C3A), 73.52 (CH2Ph), 72.87 (CH2Ph), 72.03 (C5A), 71.99 (C2B) 63.09 (C6A),
62.72, 62.68 (C6B, C6C), 55.05 (-OCH3), 44.59 (C4A), 21.15–20.75 (4C, C(O)CH3). *Assignments
may be interchanged. Compound 10β: 1H NMR (CD2Cl2): δ 8.10–7.10 (20H, m, aromatic), 5.55 (1H,
dd, J1,2=1.8, J2,3=3.1 Hz, H2B), 5.33 (1H, d, H1A), 5.28 (1H, dd, J1,2=2.7, J2,3=4.8 Hz, H2A), 5.25–5.19
(2H, m, H3A, H5A), 5.18 (1H, m, H1B), 4.90–4.54 (6H, CH2P0h), 4.81 (1H, d, J1,2=1.9 Hz, H1C), 4.24
0
(1H, dd, J5,6=4.0, J6,6 =12.1 Hz, H6A), 4.10–3.93 (4H, m, H6A , H3B, H2C, H4B*), 3.92–3.79 (7H, m,
H3C, H4C*, H4A, H6B, H6B0, H6C, H6C0), 3.78–3.67 (2H, m, H5C*, H5B*), 3.35 (3H, s, OCH3),
2.01–1.85 (4s, 3H each, C(O)CH3). 13C NMR (CD2Cl2): δ 171.18–170.13 (4C, C(O)CH3), 165.54