2050
R. S. Talan et al. / Carbohydrate Research 344 (2009) 2048–2050
general procedure described earlier with a reaction time of 30 min.
The crude product was purified by silica gel flash column chroma-
tography (6 ꢀ 3 cm) using MeOH–CHCl3 (1:19): yield 65%; Rf = 0.5
(1:9 MeOH–CHCl3); 1H NMR (600 MHz, CDCl3): d 1.96 (s, 3H,
CH3CO), 1.98 (s, 3H, CH3CO), 2.05 (s, 3H, CH3CO), 2.07 (s, 3H,
CH3CO), 2.09 (s, 3H, CH3CO), 3.77 (m, 1H, H-5), 4.08 (dd, 1H,
J = 1.8, 12.6 Hz, H-6), 4.13 (dd, 1H, J = 10.2, 18.6 Hz, H-2), 4.29
(dd, 1H, J = 4.8, 12.6 Hz, H-60), 5.04–5.13 (m, 3H, H-1, H-3 and H-
4), 6.16 (d, 1H, J = 8.4 Hz, NHAcC-2), 7.02 (d, 1H, J = 8.4 Hz, NHAcC-
1); 13C NMR (150 MHz, CDCl3): d 20.8 (CH3CO), 20.9 (CH3CO),
21.0 (CH3CO), 23.4 (CH3CO), 23.6 (CH3CO), 53.6, 61.9, 67.9, 73.2,
73.6, 80.5 (C-1), 169.5 (C@O), 171.0 (C@O), 171.2 (C@O), 172.2
(C@O), 172.3 (C@O). This compound was reported in the
literature.12
2.07 (s, 3H, CH3CO), 2.08 (s, 3H, CH3CO), 2.67 (dd, 1H, J = 4.2,
16.2 Hz, Asp-b-CH), 2.94 (dd, 1H, J = 4.2, 16.2 Hz, Asp-b-CH),
3.72–3.75 (m, 1H, H-5), 4.06 (dd, 1H, J = 1.8, 12.0 Hz, H-60), 4.08–
4.13 (m, 1H, H-2), 4.31 (dd, 1H, J = 4.2, 12.0 Hz, H-6), 4.56–4.57
(m, 1H, Asp-
a-CH), 5.01–5.04 (t, 2H, J = 8.4 Hz, H-1, H-4), 5.12–
5.20 (m, 3H, H-3, OCH2Ph), 5.55 (d, 1H, J = 8.4 Hz, Asp-
a-NH),
5.96 (d, 1H, J = 7.8 Hz, NHAcC-2), 7.04 (d, 1H, J = 8.4 Hz, NHAcC-1),
7.33–7.37 (m, 5H, aromatic); 13C NMR (150 MHz, CDCl3): 20.8
(CH3CO), 20.9 (CH3CO), 20.9 (CH3CO), 23.3 (CH3CO), 28.5
(C(CH3)3), 38.4 (Asp-b-CH2), 50.3 (Asp-a-CH), 53.6, 61.9, 67.6,
67.7, 73.0, 73.8, 80.3, 80.5 (C-1), 128.4, 128.5, 128.7, 135.5, 155.7
(C@O), 169.5 (C@O), 170.9 (C@O), 170.9 (C@O), 171.3 (C@O),
172.2 (C@O), 172.4 (C@O); mass spectrum (ESI-MS): m/z = 674.3
[M+Na]+ (C30H41N3Na O13 requires 674.3). The 1H NMR and 13C
NMR were identical to the reported compound.12
1.3.2. N-(2-Acetamido-3,4,6-tri-O-acetyl-2-deoxy-b-D-
glucopyranosyl)benzamide (10)
Acknowledgments
Glucosylsulfonamide 6 (0.030 g, 0.052 mmol) was converted to
10 (0.020 g, 0.044 mmol) as an amorphous off white cotton-like so-
lid, following the general procedure described earlier with a reac-
tion time of 30 min. The crude product was purified by silica gel
flash column chromatography (6 ꢀ 3 cm) using MeOH–CHCl3
(1:19): yield 85%; Rf = 0.62 (1:9 MeOH/CHCl3); 1H NMR
(600 MHz, CDCl3): d 1.92 (s, 3H, CH3CO), 2.07 (s, 3H, CH3CO),
2.09 (s, 3H, CH3CO), 2.11 (s, 3H, CH3CO), 3.86 (m, 1H, H-5), 4.12
(dd, 1H, J = 1.8, 12.0 Hz, H-6), 4.28 (dd, 1H, J = 10.2, 18.6 Hz, H-2),
4.35 (dd, 1H, J = 4.2, 12.6 Hz, H-60), 5.14 (t, 1H, J = 9.6 Hz, H-3),
5.20 (t, 1H, J = 9.6 Hz, H-4), 5.28 (dd, 1H, J = 8.4, 9.6 Hz, H-1), 6.18
(d, 1H, J = 7.8 Hz, NHAc), 7.44 (t, 2H, J = 7.2 Hz, aromatic), 7.52 (t,
1H, J = 7.2 Hz, aromatic), 7.82 (d, 2H, J = 7.8 Hz, aromatic), 7.84
(d, 1 H, J = 8.4 Hz, NHCOPh); 13C NMR (100 MHz, CDCl3): d 20.9
(CH3CO), 21.0 (CH3CO), 23.4 (CH3CO), 29.9 (CH3CO), 53.8 (C-2),
61.9 (C-6), 67.8, 73.2, 73.7, 81.4 (C-1), 127.6, 128.9, 132.5, 132.9,
167.7 (C@O), 169.5 (C@O), 170.9 (C@O), 172.4 (C@O), 172.6
(C@O); mass spectrum (HRMS): m/z = 473.1545 [M+Na]+
(C21H26N2NaO9 requires 473.1536). This compound was reported
in the literature.12
This work was supported in part by grants from The University
of Toledo deArce Memorial Endowment Fund, Elsa U. Pardee Foun-
dation, and The Ohio Cancer Research Associates.
Supplementary data
Supplementary data associated with this article can be found, in
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a
1.3.3. Benzyl N -tert-butoxycarbonyl-N-(2-acetamido-3,4,6-tri-
O-acetyl-2-deoxy-b-D-glucopyranosyl)-L-asparaginate (12)
Glucosylsulfonamide 6 (0.031 g, 0.054 mmol) was converted to
12 (0.024 g, 0.037 mmol) as an amorphous light green solid, fol-
lowing the general procedure described earlier with a reaction
time of 60 min. The crude product was purified by silica gel flash
column chromatography (10 ꢀ 2.5 cm) using hexane–CHCl3–
MeOH–acetone (60:30:5:5): yield 69%; Rf = 0.09 (60:30:5:5,
hexane–CHCl3–MeOH–acetone); 1H NMR (600 MHz, CDCl3):
1.42 (s, 9H, C(CH3)3), 1.95 (s, 3H, CH3CO), 2.05 (s, 3H, CH3CO),
d