Fraser-Reid et al.
128.50, 128.45, 128.41, 128.39, 128.34, 128.25, 128.15, 128.09,
127.92, 127.90, 127.81, 127.77, 127.66, 127.59, 127.50, 127.39,
127.34, 118.15, 100.27, 100.08, 99.11, 98.55, 98.28, 82.10, 81.76,
81.58, 80.60, 80.15, 80.07, 79.83, 79.46, 79.30, 78.02, 76.20, 76.10,
75.99, 75.47, 75.23, 75.12, 75.05, 74.98, 74.77, 74.64, 74.10, 73.83,
73.12, 73.05, 72.89, 72.76, 72.50, 72.43, 72.04, 71.94, 71.86, 71.57,
71.47, 71.18, 71.08, 71.92, 70.74, 70.30, 69.17, 68.18, 68.01, 66.56,
66.15, 63.57, 63.19, 27.36, 19.98; MS for C194H204O38Si calcd
3171.76, found 3195.3 (M + Na).
69.23, 68.98, 68.86, 67.67, 66.80, 66.61, 65.87, 69.97, 64.75, 63.19,
60.79, 27.29, 19.80; MS for C350H356O66Si calcd 5642.43, found
5667.7 (M + Na).
(2,3,4-Tri-O-benzyl-6-O-tert-butyldiphenylsilyl-r-D-mannopy-
ranosyl)-(1f2)-(3,4,6-tri-O-benzyl-r-D-mannopyranosyl)-(3,4-
di-O-benzyl-r-D-mannopyranosyl)-(1f6)-{3,4,6-tri-O-benzyl-r-
D-mannopyranosyl}-(3,4-di-O-benzyl-r-D-mannopyranosyl)-(1f6)-
{2-O-benzoyl-3,4,6-tri-O-benzyl-r-D-mannopyranosyl}-(3,4-di-
O-benzyl-r-D-mannopyranosyl)-(1f6)-{3,4-di-O-benzyl-r-D-
mannopyranosyl}-(2,3,4-tri-O-benzyl-r-D-mannopyranosyl)-
(1f6)-1-O-allyl-3,4,5-tri-O-benzyl-D-myoinositol (42b). The
dodecasaccharide 42a (0.460 g, 0.081 mmol) was dissolved in
CH2Cl2/CH3OH and treated with sodium methoxide (excess) for 2
days to remove all the benzoate groups. The reaction was worked
in the usual way to obtain the desired compound 42b (0.371, 88%):
1H NMR (400 MHz, CDCl3) δ 7.80 (d, J ) 6.8 Hz, 2H), 7.69 (d,
J ) 6.8 Hz, 2H), 6.94-7.47 (m, 166H), 5.80 (m, 1H), 5.54 (s,
1H), 3.11-5.32 (m, 151H), 3.01 (d, J ) 10.4 Hz, 2H), 2.77 (bs,
1H), 2.55 (bs, 1H), 2.49 (bs, 2H), 2.44 (bs, 1H), 1.07 (s, 9H); 13C
NMR (75 MHz, CDCl3) δ 139.28, 139.24, 138.96, 138.87, 138.83,
138.76, 138.73, 138.62, 138.57, 138.48, 138.36, 138.10, 138.01,
137.91, 137.85, 137.70, 137.67, 136.27, 135.89, 134.17, 134.06,
133.85, 130.20, 129.70, 129.60, 128.67, 128.53, 128.42, 128.35,
128.28, 128.23, 128.08, 127.97, 127.84, 127.77, 127.72, 127.63,
127.47, 127.34, 127.12, 126.86, 126.77, 126.73, 118.16, 102.13,
101.91, 101.74, 101.29, 100.28, 99.54, 99.32, 98.85, 98.23, 81.84,
81.58, 81.00, 80.85, 80.66, 80.58, 79.88, 79.72, 79.52, 79.27, 78.89,
76.78, 76.46, 76..02, 75.66, 75.54, 75.41, 75.25, 75.18, 74.61, 74.48,
73.92, 73.69, 73.58, 73.54, 73.18, 73.07, 72.85, 72.79, 72.43, 72.33,
72.16, 71.94, 71.76, 71.54, 71.19, 71.00, 70.74, 70.51, 70.31, 69.16,
68.80, 68.04, 66.54, 64.52, 63.16, 27.23, 19.75; MS for
(2,3,4-Tri-O-benzyl-6-O-tert-butyldiphenylsilyl-r-D-mannopyra-
nosyl)-(1f2)-(3,4-di-O-benzyl-r-D-mannopyranosyl)-(1f6)-(3,4-di-
O-benzyl-r-D-mannopyranosyl)-(1f6)-(3,4-di-O-benzyl-r-D-man-
nopyranosyl)-(1f6)-(3,4-di-O-benzyl-r-D-mannopyranosyl)-(1f6)-
(2,3,4-tri-O-benzyl-r-D-mannopyranosyl)-(1f6)-1-O-allyl-3,4,5-tri-
O-benzyl-D-myoinositol (41b). Compound 41a (0.355 g g, 0.120
mmol) was debenzoylated under the usual conditions to get
1
compound 41b (0.280 g, 85%): H NMR (300 MHz, CDCl3) δ
7.78 (d, J ) 7.5 Hz, 2H), 7.66 (d, J ) 7.8 Hz, 2H), 6.96-7.45 (m,
91H), 5.78 (m, 1H), 5.49 (s, 1H), 5.30 (s, 2H), 5.04-5.27 (m, 2H),
3.20-4.96 (m, 84H), 2.40 (bs, 5H), 1.08 (s, 9H); 13C NMR (75
MHz, CDCl3) δ 139.25, 139.16, 138.89, 138.88, 138.82, 138.69,
138.66, 138.60, 138.50, 138.30, 138.14, 137.99, 137.92, 137.83,
136.26, 135.86, 134.14, 134.10, 133.88, 129.65, 129.55, 128.73,
128.71, 128.56, 128.53, 128.49, 128.47, 128.44, 128.38, 128.32,
128.24, 128.13, 128.05, 127.90, 127.86, 127.79, 127.75, 127.63,
127.56, 127.43, 127.37, 127.31, 125.51, 118.12, 100.14, 100.12,
99.83, 99.72, 99.12, 98.24, 82.04, 81.74, 81.54, 80.56, 80.12,
79.833, 79.76, 79.43, 79.27, 76.19, 76.08, 75.96, 75.49, 75.40,
75.17, 75.12, 75.05, 74.99, 74.75, 74.63, 74.40, 74.24, 74.14, 73.93,
73.09, 73.03, 72.88, 72.73, 72.48, 72.41, 72.16, 71.98, 71.41, 71.05,
70.85, 70.73, 70.65, 69.09, 68.43, 68.15, 67.97, 66.57, 66.43, 66.21,
66.05, 63.15, 62.28, 27.22, 19.73; MS for C180H196O36Si calcd
2963.55, found 2987.0 (M + Na).
C315H336O61Si calcd 5126.09, found 5155.3 (M + Na).
(2,3,4-Tri-O-benzyl-6-O-tert-butyldiphenylsilyl-r-D-mannopyra-
nosyl)-(1f2)-{2,3,4,6-tetra-O-benzyl-r-D-mannopyranosyl}-(3,4-di-
O-benzyl-r-D-mannopyranosyl)-(1f6)-{2,3,4,6-tetra-O-benzyl-r-
D-mannopyranosyl}-(3,4-di-O-benzyl-r-D-mannopyranosyl)-(1f6)-
{2,3,4,6-tri-O-benzyl-r-D-mannopyranosyl}-(3,4-di-O-benzyl-r-D-
mannopyranosyl)-(1f6)-{2,3,4,6-tetra-O-benzyl-r-D-mannopyra-
nosyl}-(2,3,4-tri-O-benzyl-r-D-mannopyranosyl)-(1f6)-1-O-allyl-
3,4,5-tri-O-benzyl-D-myoinositol (42c). The pentaol 42b (0.520 g,
0.102 mmol) was exhaustively benzylated by dissolving in DMF
(6 mL). After the mixture was cooled to 0 °C, NaH (0.040 g, 10
equiv) was added and stirred for 0.5 h. Benzyl bromide (100 µL)
and TBAI (20 mg) were introduced, and stirring was maintained
at 0 °C for 1 h. TLC was checked, and workup yielded compound
(2,3,4-Tri-O-benzyl-6-O-tert-butyldiphenylsilyl-r-D-mannopy-
ranosyl)-(1f2)-{2-O-benzoyl-3,4,6-tri-O-benzyl-r-D-mannopy-
ranosyl}-(3,4-di-O-benzyl-r-D-mannopyranosyl)-(1f6)-{2-O-
benzoyl-3,4,6-tri-O-benzyl-r-D-mannopyranosyl}-(3,4-di-O-benzyl-
r-D-mannopyranosyl)-(1f6)-{2-O-benzoyl-3,4,6-tri-O-benzyl-r-
D-mannopyranosyl}-(3,4-di-O-benzyl-r-D-mannopyranosyl)-(1f6)-
{2,6-di-O-benzoyl-3,4,-di-O-benzyl-r-D-mannopyranosyl}-(2,3,4-
tri-O-benzyl-r-D-mannopyranosyl)-(1f6)-1-O-allyl-3,4,5-tri-O-
benzyl-D-myoinositol (42a). The heptasaccharide pentaol 41b
(0.279 g, 0.094 mmol) and mannosyl trichloroacetimidate donor
20 (0.642 g, 10 equiv) were dissolved in a small amount of toluene
and evaporated to dryness. The mixture was dried under vacuum
for about 4 h and dissolved in 15 mL of dry ether. Molecular sieves
were added, the reaction mixture was cooled to 0 °C, and
triethylsilyl triflate(50 µL) was added. The mixture was stirred for
10 min, checked by TLC, and quenched with triethylamine. The
reaction mixture was filtered and purified by chromatography gave
1
42c (0.525 g, 93%): H NMR (300 MHz, CDCl3) δ 7.84 (d, J )
7.8 Hz, 2H), 7.73 (d, J ) 8.1 Hz, 2H), 7.01-7.48 (m, 191H), 5.80
(m, 1H), 5.56 (s, 1H), 3.20-5.34 (m, 161H), 1.13 (s, 9H); 13C NMR
(75 MHz, CDCl3) δ 139.29, 139.11, 138.92, 138.79, 138.61, 138.57,
138.38, 138.21, 137.89, 137.76, 137.65, 137.56, 136.31, 135.92,
134.22, 134.10, 133.89, 129.73, 129.63, 128.76, 128.62, 128.50,
128.47, 128.38, 128.33, 128.30, 128.20, 128.15, 127.99, 127.87,
127.81, 127.77, 127.71, 127.65, 127.59, 127.52, 127.37, 127.24,
127.01, 126.91, 126.71, 118.15, 100.10, 99.93, 99.75, 99.47, 98.75,
98.36, 81.95, 81.79, 81.59, 80.97, 80.80, 80.59, 80.36, 79.97, 79.71,
79.64, 79.30, 78.18, 76.56, 76.00, 75.57, 75.38, 75.26, 75.12, 74.83,
74.63, 74.39, 74.05, 73.61, 73.20, 73.16, 72.84, 72.47, 72.37, 72.19,
72.06, 71.45, 71.07, 70.70, 70.55, 69.45, 69.23, 69.08, 66.78, 66.02,
65.59, 63.19, 27.27, 19.78; MS for C350H366O61Si calcd 5576.70,
found 5602.8 (M + Na).
1
the dodecasaccharide 42a (0.461 g, 86%): H NMR (300 MHz,
CDCl3) δ 8.02-8.11 (m, 10H), 7.77 (d, J ) 6.9 Hz, 2H), 7.67 (d,
J ) 7.5 Hz, 2H), 7.51-7.57 (m, 5H), 6.99-7.44 (m, 176H), 5.83
(dd, J ) 1.6, 3.60 Hz, 1H), 5.79 (dd, J ) 1.8, 3.00 Hz, 2H), 5.75
(dd, J ) 1.8, 3.00 Hz, 1H), 5.72 (m, 1H), 5.67 (dd, J ) 1.8, 3.00
Hz, 1H), 5.43 (s, 1H), 5.14-5.24 (m, 5H), 3.02-5.10 (m, 139H),
1.08 (s, 9H); 13C NMR (75 MHz, CDCl3) δ 165.58, 165.49, 165.45,
139.31, 139.08, 139.04, 138.95, 138.86, 138.80, 138.76, 138.57,
138.50, 138.41, 138.05, 137.93, 137.90, 137.86, 137.74, 136.33,
135.94, 134.22, 134.10, 133.90, 133.19, 130.42, 130.29, 130.23,
129.76, 129.67, 129.32, 128.90, 128.74, 128.60, 128.59, 128.53,
128.43, 128.39, 128.31, 128.25, 128.14, 128.06, 128.02, 127.97,
127.90, 127.81, 127.72, 127.68, 127.65, 127.62, 127.56, 127.47,
127.38, 127.18, 127.08, 126.99, 126.96, 126.89, 126.89, 118.18,
100.08, 99.72, 99.62, 99.56, 99.40, 98.42, 81.88, 81.62, 81.04,
80.44, 80.05, 79.86, 79.60, 79.33, 79.23, 79.17, 79.11, 78.94, 78.12,
77.90, 76.04, 75.63, 75.44, 75.27, 75.08, 74.80, 74.64, 74.27, 73.98,
73.86, 73.77, 73.60, 73.20, 72.83, 72.70, 72.62, 72.20, 72.05, 71.88,
71.71, 71.50, 71.39, 71.26, 71.09, 70.82, 70.62, 70.52, 70.38, 69.40,
(2,3,4-tTri-O-benzyl-r-D-mannopyranosyl)-(1f2)-{2,3,4,6-tetra-
O-benzyl-r-D-mannopyranosyl}-(3,4-di-O-benzyl-r-D-mannopyra-
nosyl)-(1f6)-{2,3,4,6-tetra-O-benzyl-r-D-mannopyranosyl}-(3,4-di-
O-benzyl-r-D-mannopyranosyl)-(1f6)-{2,3,4,6-tri-O-benzyl-r-D-
mannopyranosyl}-(3,4-di-O-benzyl-r-D-mannopyranosyl)-(1f6)-
{2,3,4,6-tetra-O-benzyl-r-D-mannopyranosyl}-(2,3,4-tri-O-benzyl-
r-D-mannopyranosyl)-(1f6)-1-O-allyl-3,4,5-tri-O-benzyl-D-
myoinositol (43a). The dodecasaccharide 42c (0.520 g, 0.093 mmol)
was dissolved in dry THF (10 mL), and molecular seives were
9742 J. Org. Chem. Vol. 73, No. 24, 2008