Glycoconj J
3-(Benzyloxycarbonylamino)propyl O-
(NIS; 288 mg, 1.28 mmol), TfOH (35 μL) in dry CH2Cl2
(22 mL) as described for 16, to afford pure compound 25
(1.3 g, 72 %); yellow oil; [α]D25 + 5 (c 1.5, CHCl3); IR: 2869,
2366, 1731, 1506, 1452, 1272, 1098, 1069, 708 cm−1; 1H NMR
(300 MHz, CDCl3): δ 7.26–6.94 (m, 59 H, Ar-H), 5.71 (d,
J = 3.6 Hz, 1 H, H-1D), 5.70–5.59 (m, 2 H, H-4B, H-1E), 5.23
(d, J = 8.1 Hz, 1 H, H-1A), 5.19 (brs, 2 H, COOCH2Ph), 5.09
(dd, J = 11.6 Hz, 2 H, PhCH2), 4.91 (dd, J = 11.4 Hz. 2 H,
PhCH2), 4.77 (d, J = 7.8 Hz, 1 H, H-1B), 4.76–4.71 (m, 2 H,
PhCH2), 4.63–4.44 (m, 10 H, PhCH2), 4.35–4.19 (m, 5 H,
H-2A, H-5A, H-6abA, H-5B), 4.18–4.05 (m, 2 H, H-2B, H-5E),
4.04–3.96 (m, 4 H, H-3A,H-2D, H-3D, H-4E), 3.93–3.72 (m, 6 H,
H-4A, H-6abB, H-5D, H-6abE), 3.60–3.42 (m, 6 H, H-3B, H-4D,H-
2E, H-3E, −OCH2-), 3.33–3.29(m, 2 H, NCH2-), 2.05 (s, 3 H,
COCH3), 2.02–1.95 (m, 2 H, −CH2-), 1.21 (d, J = 6.6 Hz, 3 H,
CH3), 0.99 (s,9 H, SiC(CH3)3); 13C NMR (75 MHz, CDCl3): δ
170.5 (COCH3), 168.6, 168.1(CO, Phth), 156.7 (COOCH2Ph),
138.4–123.0 (Ar-C), 100.6(C-1B), 98.1 (C-1D), 97.9 (C-1A),
97.1 (C-1E), 80.1 (C-2B), 79.0 (2 C, C-2D, C-2E), 78.5 (C-3A),
77.8 (C-3B), 77.2 (2 C, C-5B, C-3E), 77.1 (C-3D), 76.0 (PhCH2),
75.7 (2 C, C-4A, C-4D), 75.3 (C-5D), 75.2 (2 C, PhCH2), 74.1
(PhCH2), 73.7 (PhCH2), 73.6 (PhCH2), 73.2 (PhCH2), 73.1
(PhCH2), 72.4 (C-4E), 70.6 (C-4B), 69.7 (C-5A), 68.9
-(OCH2-), 68.5 (COOCH2Ph), 68.0 (C-6E), 66.6 (C-5E), 65.9
(C-6B), 61.7 (C-6A), 56.8 (C-2A), 50.9 (NCH2-), 29.6 (−CH2-),
26.9 (SiC(CH3)3), 21.4 (COCH3), 19.8 (SiC(CH3)3), 17.1
(CH3); ESI-MS: C117H126N2NaO24Si requires m/z 1993.8472;
found: m/z 1993.8466 [M + Na]+.
(2,3,4-tri-O-benzyl-α-L-fucopyranosyl)-(1 → 2)-O-
(4-O-acetyl-6-O-benzyl-β-D-galactopyranosyl)-
(1 → 4)-6-O-t-butyldiphenylsilyl-2-deoxy-2-
phthalimido-β-D-glucopyranoside (24)
Triethyl orthoacetate (0.37 mL, 1.99 mmol) and p-
toluenesulfonic acid (0.3 g, 1.99 mmol) were added to a solu-
tion of diol 23 (1.4 g, 0.99 mmol) in dry DMF (15 mL). The
reaction mixture was stirred at room temperature for 2 h. The
solvents were removed under reduced pressure and a solution
of the intermediate orthoester in 80 % aqueous AcOH (50 mL)
was stirred at room temperature for 1 h. The reaction mixture
was evaporated to dryness and the product was purified over
SiO2 using hexane–EtOAc (3:1) as eluent to furnish 24 (1.15 g,
25
79 %) as a colourless syrup; [α]D + 45 (c 1.5, CHCl3); IR:
3030, 2932, 2880, 1775, 1716, 1454, 1389, 1237, 1080, 754,
700 cm−1; 1H NMR (500 MHz, CDCl3): δ 7.81–7.66 (m, 6 H,
Ar-H), 7.36–7.24 (m, 33 H, Ar-H), 5.45(d, J = 3.5 Hz, 1 H,
H-4B), 5.20 (d, J = 8.5 Hz, 1 H, H-1A), 5.06 (brs, 2 H,
COOCH2Ph), 4.97 (d, J = 11.6 Hz, 1 H, PhCH2), 4.94 (d,
J = 3.4 Hz, 1 H, H-1D), 4.93 (d, J = 11.7 Hz, 1 H, PhCH2),
4.81 (d, J = 11.6 Hz, 1 H, PhCH2), 4.80 (d, J = 11.6 Hz, 1 H,
PhCH2), 4.74–4.72 (m, 2 H, PhCH2), 4.66 (d, J = 8.0 Hz, 1 H,
H-1B), 4.60 (d, J = 11.6 Hz, 1 H, PhCH2), 4.53 (d, J = 11.6 Hz,
1 H, PhCH2), 4.48–4.46 (m, 1 H, H-3A), 4.44 (d, J = 11.7 Hz,
1 H, PhCH2), 4.26 (dd, J = 8.5, 2.2 Hz, 1 H, H-2A), 4.07–4.04
(m, 3 H, H-4A, H-6aA, H-3D), 3.89 (d, J = 11.2 Hz, 1 H, H-6bA),
3.86–3.83 (m, 2 H, H-5B, H-2D), 3.72–3.70 (m, 1 H, H-4D),
3.60–3.57 (m, 2 H, H-2B, H-3B), 3.52–3.48 (m, 3 H, H-6aB,
−OCH2-), 3.43–3.48 (m, 3 H, H-5A, H-6bB, H-5D), 3.15–3.11
(m, 2 H, NCH2-), 1.90 (S, 3 H, COCH3), 1.72–1.69 (m, 2 H,
−CH2-), 1.02 (s, 9 H, SiC(CH3)3), 0.75 (d, J = 6.4 Hz, 3 H,
CH3); 13C NMR (75 MHz, CDCl3): δ 170.3 (COCH3), 168.6,
168.1(CO, Phth), 156.4 (COOCH2Ph), 138–127 (Ar-C), 101.4
(C-1B), 101.1 (C-1D), 98.1 (C-1A), 80.9 (C-3B), 78.9 (C-2B),
77.6 (2 C, C-3A, C-2D), 77.3(C-4A), 75.0 (C-3D), 74.8 (PhCH2),
74.5 (PhCH2), 73.7 (PhCH2), 73.1 (PhCH2), 72.6 (C-5A), 72.1
(C-5D), 69.3 (C-4D), 69.2 (C-5B), 68.0 (C-4B), 67.8 (PhCH2),
67.0 (−OCH2-), 66.5 (C-6B), 61.8 (C-6A), 56.6 (C-2A), 38.6
(NCH2-), 29.6 (−CH2-), 26.9 (SiC(CH3)3), 20.7 (COCH3),
19.5 (SiC(CH3)3), 16.8 (CH3); ESI-MS: C83H92N2NaO19Si re-
quires m/z 1471.5857; found: m/z 1471.5866 [M + Na]+.
3-(Benzyloxycarbonylamino)propyl O-
(3,4,6-tri-O-acetyl-2-azido-2-deoxy-α-D-
galactopyranosyl)-(l→3)-[O-(2,3,4-tri-O-benzyl-α-L-
fucopyranosyl)-(l→2)]-O-(4-O-acetyl-6-O-
benzyl-β-D-galactopyranosyl)-(1→4)-6-O-t-
butyldiphenylsilyl-2-deoxy-2-phthalimido-β-D-
glucopyranoside (26)
Prepared from compound 24 (2.0 g,1.38 mmol),
trichloacetimidate donor 15 (0.79 g, 1.66 mmol), MS-4 Å
(1 g), TMSOTf (50 μL) in dry CH2Cl2 (40 mL) as described
for 17, to afford pure compound 26 (1.85 g, 77 %); yellow oil;
25
[α]D + 26.3 (c 1.5, CHCl3); IR (neat): 2869, 2208, 1952,
1629, 1527, 1463, 1216, 1059, 967 cm−1 1H NMR
;
(500 MHz, CDCl3): δ 7.71–7.56 (m, 6 H, Ar-H), 7.37–7.25
(m, 33 H, Ar-H), 5.45 (d, J = 3.8 Hz, 1 H, H-1D), 5.32 (d,
J = 3.1 Hz, 1 H, H-1E), 5.31–5.29 (m, 1 H, NHCbz), 5.21 (d,
J = 8.1 Hz, 1 H, H-1A), 5.15 (brs, 2 H, COOCH2Ph), 5.11 (d,
J = 11.6 Hz, 1 H, PhCH2), 5.03–4.99 (m, 1 H, H-4E), 4.97 (d,
J = 11.7 Hz, 1 H, PhCH2), 4.94 (dd, J = 3.3, 10.2, Hz, 1 H,
H-3E), 4.83 (d, J = 11.6 Hz, 1 H, PhCH2), 4.78 (d, J = 11.7 Hz,
1 H, PhCH2), 4.72 (d, J = 11.6 Hz, 1 H, PhCH2), 4.65 (d,
J = 11.6 Hz, 1 H, PhCH2), 4.62 (m, 1 H, H-3A), 4.60–4.56 (m,
1 H, H-2E), 4.50 (ABq, 2 H, PhCH2), 4.42 (d, J = 7.7 Hz, 1 H,
3-(Benzyloxycarbonylamino)propyl O-
(2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl)-(l→3)-
[O-(2,3,4-tri-O-benzyl-α-L-fucopyranosyl)-(l→2)]-O-
(4-O-acetyl-6-O-benzyl-β-D-galactopyranosyl)-(1→4)-
6-O-t-butyldiphenylsilyl-2-deoxy-2-phthalimido-β-D-
glucopyranoside (25)
Prepared from compound 24 (1.3 g, 0.89 mmol), thioglycoside
14 (680 mg, 1.07 mmol), MS-4 Å (600 mg), N-Iodosuccinimide