V. Subramaniam et al. / Tetrahedron: Asymmetry 16 (2005) 553–567
565
1H, J = 11.9 Hz), 4.46 (d, 1H, J = 11.0 Hz), 3.87–3.94
(m, 4H), 3.83 (dd, 1H, J = 9.5, 9.5 Hz), 3.79 (dd, 1H,
J = 1.6, 2.0 Hz), 3.73 (dd, 1H, J = 2.6, 11.7 Hz), 3.61–
3.71 (m, 4H), 3.58 (ddd, 1H, J = 6.8, 6.8, 9.6 Hz), 3.41
(s, 3H), 3.33 (ddd, 1H, J = 6.8, 6.8, 9.6 Hz), 1.92 (br s,
1H), 1.49–1.51 (m, 2H), 1.26–1.32 (m, 10H), 0.88 (t,
3H, J = 6.8 Hz); 13C NMR (125.8 MHz, CDCl3) dC
139.0, 138.9, 138.8, 138.6, 128.9, 128.8, 128.7, 128.5,
128.4, 128.3, 128.2, 128.1, 128.0, 98.3, 98.1, 80.8, 79.4,
77.8, 75.6, 75.6, 75.6, 75.1, 75.0, 73.4, 72.6, 72.5, 72.1,
72.1, 68.1, 66.5, 62.7, 59.5, 32.3, 29.9, 29.8, 29.7, 26.6,
23.1, 14.6. HR-ESI-MS calcd for C56H70O11 [M+Na]+
941.4816, found 941.4791.
hexane–EtOAc) to give 33 (100 mg, 83%) as a light yel-
low syrup. Rf 0.53 (2:1 hexane–EtOAc); [a]D = +29.5 (c
1
0.2, CHCl3); H NMR (400 MHz, CDCl3) dH 7.21–7.37
(m, 20H, Ph), 4.93 (d, 1H, J1 ,2 = 6.5 Hz, H-10), 4.86 (d,
1H, J = 10.6 Hz, benzylic CH2), 4.81 (d, 1H,
J1,2 = 1.5 Hz, H-1), 4.74 (d, 1H, J = 12.2 Hz, benzylic
CH2), 4.73 (d, 1H, J = 10.5 Hz, benzylic CH2), 4.62–
4.68 (m, 4H, benzylic CH2), 4.47 (d, 1H, J = 11.8 Hz,
benzylic CH2), 4.36 (dd, 1H, J1,2 = J2,3 = 2.0 Hz, H-2),
4.23–4.27 (m, 3H, H-3, H-40, H-50), 3.87–3.94 (m, 4H,
0
0
H-3, H-4, H-5, H-6b0), 3.81 (dd, 1H, J5 ,6a = 1.4 Hz,
0
0
J6a ,6b = 11.0 Hz, H-6a0), 3.73–3.76 (m, 2H, H-6a, H-
6b), 3.63 (ddd, 1H, J = 6.6, 6.6, 9.6 Hz, octyl OCH2),
0
0
3.49 (dd, 1H, J1 ,2 = 6.5 Hz, J2 ,3 = 1.2 Hz, H-20), 3.41
(s, 3H, OCH3), 3.32 (ddd, 1H, J = 6.6, 6.6, 9.6 Hz, octyl
OCH2), 1.47–1.50 (m, 2H, octyl CH2), 1.25–1.32 (m,
10H, octyl CH2), 0.88 (t, 3H, J = 7.1 Hz, octyl CH3);
13C NMR (125.8 MHz, CDCl3) dC 138.8, 138.7, 138.5,
137.4, 128.5, 128.3, 128.3, 128.2, 127.9, 127.8, 127.7,
127.6, 127.6, 127.5, 127.5, 102.0 (C-10), 97.6 (C-1),
80.1, 78.0, 77.3, 75.5, 75.2, 75.2, 74.9, 72.6, 72.6, 72.5,
71.7, 71.3, 69.7, 68.2, 67.6 (ring and benzylic C,
octyl OCH2), 59.0 (OCH3), 31.8 (octyl CH2), 29.4 (octyl
CH2), 29.4 (octyl CH2), 29.2 (octyl CH2), 26.2 (octyl
CH2), 22.7 (octyl CH2), 14.1 (octyl CH3). HR-ESI-MS
calcd for C49H62O10 [M+Na]+ 833.4241, found
833.4232.
0
0
0
0
3.21. Octyl 3,4-di-O-benzyl-6-deoxy-2-O-methyl-6-
phthalimido-a-D-mannopyranosyl-(1!6)-2,3,4-tri-O-
benzyl-a-D-mannopyranoside 32
Alcohol 31 (170 mg, 0.19 mmol), PPh3 (100 mg,
0.38 mmol), and phthalimide (43 mg, 0.29 mmol) were
dissolved in THF (8 mL) and diisopropylazodicarboxyl-
ate (75 lL, 0.38 mmol) was added. After stirring over-
night, the solution was concentrated under vacuum
and the residue was purified by chromatography (4:1
hexane–EtOAc) to give 32 (170 mg, 85%) as a colorless
syrup. Rf 0.34 (3:1 hexane–EtOAc); [a]D = +16.5 (c
0.4, CHCl3); 1H NMR (500 MHz, CDCl3) dH 7.69–
7.73 (m, 2H), 7.56–7.59 (m, 2H), 7.15–7.37 (m, 25H),
5.04 (br s, 1H), 5.03 (d, 1H, J = 11.0 Hz), 4.77 (d,
1H, J = 2.0 Hz), 4.75 (d, 1H, J = 10.8 Hz), 4.74 (d, 1H,
J = 12.2 Hz), 4.71 (d, 1H, J = 11.4 Hz), 4.67 (d, 1H,
J = 12.2 Hz), 4.62–4.64 (m, 2H), 4.52 (d, 1H,
J = 12.0 Hz), 4.51 (d, 1H, J = 11.9 Hz), 4.38 (d,
1H, J = 10.8 Hz), 4.00–4.04 (m, 1H), 3.98 (dd, 1H,
J = 7.1, 13.8 Hz), 3.90 (dd, 1H, J = 4.3, 13.8 Hz), 3.83–
3.88 (m, 2H), 3.81 (dd, 1H, J = 9.5, 9.5 Hz), 3.76 (d,
1H, J = 2.3 Hz), 3.74 (dd, 1H, J = 2.0, 2.0 Hz), 3.72
(dd, 1H, J = 9.5, 9.5 Hz), 3.54–3.59 (m, 3H), 3.51
(ddd, 1H, J = 6.8, 6.8, 9.7 Hz), 3.33 (s, 3H), 3.29 (ddd,
1H, J = 6.8, 6.8, 9.7 Hz), 1.45–1.47 (m, 2H), 1.24–1.32
3.23. Octyl 3,6-anhydro-2-O-methyl-a-D-mannopyrano-
syl-(1!6)-a-D-mannopyranoside 34
Anhydrosugar 33 (94 mg, 0.12 mmol) was dissolved in
HOAc (8 mL), and 10% Pd/C (35 mg) was added. The
solution was stirred overnight under an H2 atmosphere
and then the catalyst was separated by filtration and
washed with CH3OH (10 mL). After concentrating the
filtrate and the washings, the product was purified by
chromatography (9:1 CH2Cl2–CH3OH) on Iatrobeads
to give 34 (34 mg, 65%) as a foam. Rf 0.36 (9:1
CH2Cl2–CH3OH); [a]D = +74.8 (c 0.2, CH3OH); 1H
NMR (800 MHz, CD3OD) dH 4.89 (d, 1H,
(m, 10H), 0.87 (t, 3H, J = 6.9 Hz); 13C
N MR
(125.8 MHz, CDCl3) dC 168.6, 139.3, 139.0, 138.9,
138.5, 134.0, 132.5, 128.9, 128.8, 128.7, 128.6, 128.5,
128.4, 128.3, 128.1, 128.0, 127.9, 127.7, 123.5, 98.2,
97.6, 80.7, 79.5, 77.5, 75.8, 75.6, 75.0, 74.9, 73.4,
73.4, 72.7, 72.4, 71.8, 71.8, 69.3, 68.0, 66.2, 59.1,
32.3, 29.9, 29.7, 29.3, 26.6, 23.1, 14.5. HR-ESI-MS
calcd for C64H73NO12 [M+Na]+ 1070.5030, found
1070.4985.
J1 ,2 = 6.6 Hz, H-10), 4.73 (d, 1H, J1,2 = 1.7 Hz, H-1),
0
0
4.25 (dd, 1H, J5 ,6b = J4 ,5 = 2.6 Hz, H-50), 4.22 (d,
0
0
0
0
1H, J3 ,4 = 6.1 Hz, H-30), 4.20 (dd, 1H, J3 ,4 = 6.1 Hz,
J4 ,5 = 2.6 Hz, H-40), 4.07 (dd, 1H, J5,6b = 5.4 Hz,
0
0
0
0
0
0
0
0
J6a,6b = 11.0 Hz, H-6b), 4.03 (d, 1H, J6a ,6b = 10.5 Hz,
H-6a0), 3.98 (dd, 1H, J5 ,6b = 2.6 Hz, J6a ,6b = 10.5 Hz,
H-6b0), 3.88 (d, 1H, J6a,6b = 11.0 Hz, H-6a), 3.80 (dd,
1H, J1,2 = 1.7 Hz, J2,3 = 3.1 Hz, H-2), 3.74 (ddd, 1H,
J = 6.6, 6.6, 9.7 Hz, octyl OCH2), 3.68–3.71 (m, 3H,
0
0
0
0
0
0
3.22. Octyl 3,6-anhydro-4-O-benzyl-2-O-methyl-a-D-
mannopyranosyl-(1!6)-2,3,4-tri-O-benzyl-a-D-manno-
pyranoside 33
H-3, H-4, H-5), 3.46 (d, 1H, J1 ,2 = 6.6 Hz, H-20), 3.49
(s, 3H, OCH3), 3.42 (ddd, 1H, J = 6.6, 6.6, 9.7 Hz, octyl
OCH2), 1.58–1.62 (m, 2H), 1.32–1.41 (m, 10H), 0.92 (t,
3H, J = 7.2 Hz); 13C NMR (150.9 MHz, CD3OD) dC
Disaccharide 31 (133 mg, 0.15 mmol) was dissolved in
CH2Cl2 (7 mL) and the solution was cooled to ꢀ40 ꢁC
and DAST (100 lL, 0.76 mmol) was added. After stir-
ring for 6 h, CH3OH was added (1 mL) and the solution
was concentrated. The residue was taken in CH2Cl2
(2 · 20 mL), washed with water (20 mL) and dried
(Na2SO4), filtered, and concentrated to a brown syrup.
The crude syrup was purified by chromatography (3:1
102.8
(C-1,
1JC,H = 161.4 Hz),
101.6
(C-1,
1JC,H = 168.1 Hz), 79.5 (C-20), 77.1 (C-40), 76.9 (C-30),
73.2 (C-5), 72.5 (C-3), 72.2 (C-2), 72.0 (C-50), 70.4 (C-
60), 69.6 (C-6), 68.6 (octyl OCH2), 68.6 (C-4), 58.8
(OCH3), 33.0 (octyl CH2), 30.6 (octyl CH2), 30.5 (octyl
CH2), 30.4 (octyl CH2), 27.4 (octyl CH2), 23.7 (octyl
CH2), 14.4 (octyl CH3). HR-ESI-MS calcd for
C21H38O10 [M+Na]+ 473.2363, found 473.2325.