R .E. J. N. Litjens et al.
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the reaction mixture was cooled to –608C. Tf2O (440 mL, 2.6 mmol) was
added, and the reaction mixture was brought to –408C. Stirring was conti-
nued for 1 hr at this temperature, after which phenyl 4-O-acetyl-2,6-di-O-
benzoyl-1-thio-b-D-galactopyranoside 4 (1.04 g, 2.0 mmol in 5 mL DCM) was
added. The reaction mixture was kept at –408C for 1 hr after which it was
slowly warmed to 08C. After 30 min at 08C the reaction mixture was cooled
to –608C, and Tf2O (400 mL, 2.4 mmol) was added. After the reaction was
kept at –608C for 10 min, 3-azidopropyl 3,6-di-O-benzyl-2-deoxy-2-phtal-
imido-b-D- glucopyranoside 5 (1.64 g, 3 mmol) was added. The mixture was
slowly warmed to 08C, after which Et3N (2 mL) was added. Standard
workup and purification gave compound 7 (1.85 g, 1.23 mmol, 61%) as a color-
less oil. Rf 0.60 (33% ethyl acetate in light petroleum). [a]2D5 þ39.2 (c ¼ 0.75,
CHCl3). 1H NMR: d (ppm) 8.10–6.83 (m, 44H, Harom), 5.54 (m, 2H, H-20,
H-40), 5.14 (d, 1H, J ¼ 3.3 Hz, H-100), 5.00 (d, 1H, J ¼ 8.5 Hz, H-1), 4.91
(d, 1H, J ¼ 12.4 Hz, –CHPh), 4.78 (d, 1H, J ¼ 8.1 Hz, H-10), 4.74 (d, 1H,
J ¼ 11.4 Hz, –CHPh), 4.63 (s, 2H, –CHPh), 4.62 (d, 1H, J ¼ 11.8 Hz,
–CHPh), 4.55 (d, 1H, J ¼ 12.0 Hz, –CHPh), 4.51 (d, 1H, J ¼ 12.4 Hz,
–CHPh), 4.44 (d, 1H, J ¼ 11.8 Hz, –CHPh), 4.42 (d, 1H, J ¼ 11.8 Hz, –CHPh),
4.35 (d, 1H, J ¼ 12.0 Hz, –CHPh), 4.29 (m, 3H, 2 ꢀ –CHPh, H-3), 4.22 (dd,
1H, J ¼ 6.5 Hz, J ¼ 11.3 Hz, H-60), 4.13 (m, 2H, H-60, H-2), 4.05 (dd, 1H,
J ¼ 8.5 Hz, J ¼ 9.9 Hz, H-4), 3.99 (dd, 1H, J ¼ 3.4 Hz, J ¼ 10.2 Hz, H-30), 3.91
(dd, 1H, J ¼ 3.3, 10.2 Hz, H-200), 3.85 (bt, 1H, J ¼ 6.9 Hz, H-500), 3.75 (m, 1H,
O–CHH–CH2), 3.67 (m, 2H, H-50, H-6), 3.58 (m, 2H, H-6, H-300), 3.41 (m, 1H,
H-5), 3.38 (m, 2H, H-600, O-CHH-CH2), 3.25 (dd, 1H, J ¼ 1.2 Hz, J ¼ 2.6 Hz,
H-400), 3.21 (dd, 1H, J ¼ 5.9 Hz, J ¼ 9.4 Hz, H-600), 3.08 (m, 2H, CH2–CH2–
N3), 1.81 (s, 3H, Ac), 1.64 (m, 2H, CH2–CH2–;CH2). 13C NMR: d (ppm) 170.2,
166.0, 164.6 (C55O), 138.7, 138.4, 138.1, 138.0 (Cq Bn), 131.5 (Cq Phth),
129.3, 129.7 (Cq Bz), 133.7–123.2 (CHarom), 100.8 (C-10), 98.3 (C-1), 94.1
(C-100), 78.8 (C-300), 78.3 (C-4), 76.9 (C-3), 75.5 (C-200), 74.8 (C-400), 74.7 (C-5),
74.5, 73.5, 73.3, 73.2, 73.1 (CH2 Bn), 72.3 (C-30), 71.4 (C-20), 71.0 (C-50), 69.8
(C-500), 69.2 (C-600), 67.8 (C-6), 65.9 (O–CH2–CH2), 65.0 (C-40), 61.7 (C-60),
55.7 (C-2), 48.0 (CH2–CH2–N3), 28.8 (CH2-CH2-CH2), 20.4 (Ac). ESI-MS:
m/z 1529.8 [M þ Na] þ . ESI-HRMS calcd for C87H86N4O20 (M þ H):
1507.5914. Found: 1507.5908.
3-Azidopropyl (2,3,4,6-Tetra-O-benzyl-a-D-
galactopyranosyl)-(1 ! 3)-(2-O-acetyl-b-D-
galactopyranosyl)-(1 ! 4)-2-acetamido-3,6-di-O-
benzyl-2-deoxy-b-D-glucopyranoside (8).
To a solution of 7 (320 mg, 0.21 mmol) in dry nBuOH (2 mL) was added
ethylene diamine (1 mL), and the mixture was heated to 908C and stirred