M. Reiner, R. R. Schmidt / Tetrahedron: Asymmetry 11 (2000) 319–335
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Hz, 5b-H), 4.35 (ddd, 1H, J6b,7b=7.8 Hz, J7b,8b=4.8 Hz, 7b-H), 4.46–4.80 (m, 5H, 4b-H, CH2Ph), 4.92
(d, 1H, J1a,2a=7.5 Hz, 1a-H), 5.37 (d, 1H, J2a,NH=8.2 Hz, NH), 7.11–7.32 (m, 10H, Ph); MALDI-MS:
[M+Na]+=881, [M+K]+=897. Anal. calcd for C45H67NO13Si (858.11): C, 62.99; H, 7.87; N, 1.63; found:
C, 62.80; H, 7.72; N, 1.38.
3.25. Acetyl O-(methyl 4,5,7,8-tetra-O-acetyl-3-deoxy-α-D-manno-2-octulopyranosonate)-(2→6)-2-
acetamido-3,4-di-O-benzyl-2-deoxy-α,β-D-glucopyranoside 27
Aqueous 80% trifluoroacetic acid (1 mL) was added to a solution of 26 (50 mg, 58 µmol) in CH2Cl2 (5
mL). The mixture was stirred for 24 h at room temperature, then concentrated and coevaporated several
times with toluene. The residue was dissolved in pyridine:Ac2O (2:1, 7 mL) and stirred for 24 h at room
temperature. Then the reaction mixture was concentrated in vacuo and the residue was purified by flash
1
chromatography (toluene:EtOAc, 1:2) to give 27 (28 mg, 55%); TLC (EtOAc): Rf 0.47; α: H NMR
0
0
(600 MHz, CDCl3) δ: 1.78–2.11 (m, 19H, COCH3, 3b-H), 2.15 (dd, 1H, J3b,3 b=12.9 Hz, J3 b,4b=5.6 Hz,
30b-H), 3.49–3.53 (m, 2H, 6a-, 4a-H), 3.67–3.74 (m, 5H, 3a-, 60a-H, COOCH3), 3.79 (ddd, 1H, J5a,6a=6.5
0
0
Hz, J5a,6 a=2 Hz, J4a,5a=10.5 Hz, 5a-H), 4.02 (dd, 1H, J7b,8b=5.3 Hz, J8b,8 b=12.2 Hz, 8b-H), 4.12 (dd,
1H, J5b,6b=1 Hz, J6b,7b=9.7 Hz, 6b-H), 4.27 (ddd, 1H, J1a,2a=3.8 Hz, J2a,3a=10.6 Hz, J2a,NH=9.1 Hz, 2a-
H), 4.54 (dd, 1H, J7b,8 b=2.6 Hz, 80b-H), 4.85–4.92 (m, 5H, CH2Ph, NH), 5.20–5.18 (ddd, 1H, 7b-H),
0
5.21 (ddd, 1H, J4b,5b=2 Hz, J3b,4b=12.0 Hz, 4b-H), 5.29 (bs, 1H, 5b-H), 6.01 (d, 1H, 1a-H), 7.28–7.36
(m, 10H, Ph); 13C NMR (150.9 MHz, CDCl3) δ: 20.7–23.2 (6C, COCH3), 31.9 (1C, 3b-C), 51.4 (1C,
2a-C), 52.8 (1C, COOCH3), 62.4 (1C, 8b-C), 62.9 (1C, 6a-C), 64.6 (1C, 5b-C), 66.2 (1C, 4b-C), 67.6
(1C, 7b-C), 68.4 (1C, 6b-C), 72.5 (1C, 5a-C), 74.8, 75.2 (2C, CH2Ph), 78.4 (1C, 4a-C), 79.6 (1C, 3a-
1
C), 91.0 (1C, 1a-C), 98.5 (1C, 2b-C), 127.9–137.7 (12C, Ph), 168.8–170.5 (7C, 1b-C, COCH3); β: H
NMR (600 MHz, CDCl3) δ: 1.76–2.16 (7s, 20H, COCH3, 3b-, 30b-H), 3.50–5.29 (m, 13H, 2a-, 3a-,
4a-, 5a-, 6a-, 60a-, 4b-, 5b-, 6b-, 7b-, 8b-, 80b-H, NH), 5.65 (d, 1H, J1a,2a=7.5 Hz, 1a-H), 7.28–7.37 (m,
10H, Ph); FAB-MS (nominal mass): [M+Na]+=868, [M+NaI]Na+=1018; MALDI-MS: [M+Na]+=869,
[M+K]+=885. Anal. calcd for C41H51NO18·2H2O (881.88): C, 55.84; H, 6.28; N, 1.59; found: C, 55.89;
H, 6.18; N, 1.34.
3.26. Thexyldimethylsilyl O-(methyl 3-O-acetyl-4,5:7,8-di-O-isopropylidene-α-D-glycero-D-talo-2-
octulopyranosonate)-(2→6)-2-acetamido-3,4-di-O-benzyl-2-deoxy-β-D-glucopyranoside 28
A solution of 24 (150 mg, 0.175 mmol) in pyridine:water (3:1, 5 mL) was treated with H2S and
stirred for 36 h. The mixture was evaporated to dryness and acetylated with pyridine:Ac2O (2:1, 6
mL) and DMAP (10 mg) for 12 h. After concentration in vacuo, the residue was purified by flash
chromatography (toluene:EtOAc, 4:1) to afford 28 (125 mg, 78%); TLC (toluene:EtOAc, 2:1): Rf
1
0.33; [α]D +21.0 (c 0.5, CHCl3); H NMR (250 MHz, CDCl3) δ: 0.09–0.10 [2s, 6H, Si(CH3)2],
0.79–0.84 [m, 12H, SiC(CH3)2CH(CH3)2], 1.32, 1.38, 1.42, 1.46 [4s, 12H, C(CH3)2], 1.54–1.60 [m,
1H, SiC(CH3)2CH(CH3)2], 1.82 (s, 3H, NHCOCH3), 2.06 (s, 3H, COCH3), 3.28–3.33 (m, 2H, 2a-, 4a-
H), 3.46 (dd, 1H, J5a,6a=8.2 Hz, J6a,6 a=10.1 Hz, 6a-H), 3.52 (dd, 1H, J5a,6 a=2.7 Hz, 60a-H), 3.61 (ddd,
1H, J4a,5a=8.6 Hz, 5a-H), 3.63 (s, 3H, COOCH3), 3.81 (dd, 1H, J4b,5b=7.4 Hz, J5b,6b=3.0 Hz, 5b-H), 4.03
0
0
0
(dd, 1H, J7b,8b=4.9 Hz, J8b,8 b=8.9 Hz, 8b-H), 4.08 (dd, 1H, J2a,3a=8.4 Hz, J3a,4a=9.9 Hz, 3a-H), 4.11 (dd,
1H, J7b,8 b=6.2 Hz, 80b-H), 4.24 (dd, 1H, J6b,7b=6.7 Hz, 6b-H), 4.44–4.80 (m, 6H, 4b-, 7b-H, CH2Ph),
0
4.95 (d, 1H, J1a,2a=7.7 Hz, 1a-H), 5.25 (d, 1H, J3b,4b=5.2 Hz, 3b-H), 5.43 (d, 1H, J2a,NH=8.2 Hz, NH),
7.16–7.34 (m, 10H, Ph); 13C NMR (150.9 MHz, CDCl3) δ: −3.7, −1.8 [2C, Si(CH3)2], 18.5–34.0 [12C,
SiC(CH3)2CH(CH3)2, COCH3, C(CH3)2], 52.2 (1C, COOCH3), 58.6 (1C, 2a-C), 64.2 (1C, 6a-C), 66.6