2504
A. Li, F. Kong / Carbohydrate Research 339 (2004) 2499–2506
(30mL) was added PdCl2 (100mg, 0.56mmol). The reac-
tion mixture was stirred at rt until TLC (2:1 petroleum
ether–EtOAc) suggested that the reaction was complete.
The mixture was then filtered, the solution was concen-
trated to dryness, and the residue was purified by flash
chromatography with 3:1 petroleum ether–EtOAc as
the eluent to give 17 (1.65g, 87%) as a foamy solid:
then concentrated, and co-evaporated with toluene
(5mL) three times. The residue was dried under high
vacuum for 2h, then dissolved in pyridine (10mL),
and benzoyl chloride (0.12mL, 0.84mmol) was added.
The reaction mixture was stirred at rt for 6h, at the
end of which time TLC (1:1 petroleum ether–EtOAc)
suggested that the reaction was finished. Excess benzoyl
chloride was destroyed by the addition of MeOH. The
mixture was concentrated and purified by chromatogra-
phy with 1:1 petroleum ether–EtOAc as the eluent to af-
ford compound 19 (547mg, 73% for two steps) as a
foamy solid. To a solution of 19 (500mg, 0.28mmol)
in CH3OH (50mL)–CH2Cl2 (50mL) was added
CH3COCl (7mL), and the mixture was stirred at rt for
72h, at the end of which time TLC (1:1 petroleum
ether–EtOAc) indicated that the reaction was complete,
then neutralized with Et3N. The reaction mixture was
concentrated, then the residue was passed through a sil-
ica gel column with 2:1 petroleum ether–EtOAc as the
eluent to give 20 (356g, 73%) as a syrup: [a]D +25.2 (c
1
[a]D +8.6 (c 1.0, CHCl3); H NMR (CDCl3): d 8.03–
7.25 (m, 15H, 3Ph), 5.58 (s, 1H, PhCH), 5.38 (dd, 1H,
J3,4 = J4,5 = 9.8Hz, H-4), 5.18 (dd, 1H, J1,2 = 8.0Hz,
J2,3 = 8.8Hz, H-2), 5.00 (d, 1H, J1,2 = 8.0Hz, H-1),
4.87 (d, 1H, J1,2 = 8.0Hz, H-1), 4.78 (dd, 1H,
J1,2 = 4.0Hz, J2,3 = 9.6Hz, H-2), 4.46 (dd, 1H,
J5,6 = 3.2Hz, J6,6 = 12Hz, H-6), 4.33–4.21 (m, 3H),
4.02 (dd, 1H, J2,3 = J3,4 = 8.8Hz, H-3), 3.84–3.71 (m,
4H), 3.47 (s, 3H, OCH3), 2.01 (s, 3H, MeCO). Anal.
Calcd for C43H42O15: C, 64.66; H, 5.30. Found: C,
64.58; H, 5.39.
3.10. Methyl 2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!3)-2-O-acetyl-4,6-O-benzylidene-b-D-glucopyranosyl-
(1!3)-2,4,6-tri-O-benzoyl-b-D-glucopyranosyl-(1!3)-2-
O-acetyl-4,6-O-benzylidene-a-D-glucopyranoside (18)
1
1.0, CHCl3); H NMR (CDCl3): d 8.09–7.17 (m, 55H,
11 Ph), 5.71 (dd, 1H, J3,4 = J4,5 = 9.6Hz, H-4), 5.28–
5.17 (m, 4H), 5.10–5.03 (m, 2H), 5.01 (d, 1H,
J1,2 = 8.0Hz, H-1), 4.83 (dd, 1H, J3,4 = J4,5 = 8.8Hz,
H-4), 4.80 (d, 1H, J1,2 = 3.6Hz, H-1), 4.70 (d, 1H,
J1,2 = 8.0Hz, H-1), 4.54 (d, 1H, J1,2 = 8.0Hz, H-1),
4.47 (dd, 1H, J5,6 = 2.4Hz, J6,6 = 12Hz, H-6), 4.35 (dd,
1H), 4.25 (dd, 1H), 4.15–4.3.89 (m, 9H), 3.76–3.63 (m,
3H), 3.62 (dd, 1H, J1,2 = 3.6Hz, J2,3 = 9.2Hz, H-2),
3.43 (s, 3H, OCH3), 1.84 (s, 3H, MeCO); 13C NMR
(100MHz, CDCl3): d 169.9, (1C, 1MeCO), 166.0,
165.8, 165.8, 165.7, 165.6, 164.9, 164.9, 164.8, 164.6,
164.6, 164.2 (11C, 11PhCO), 101.0, 101.0, 100.6 (3b-C-
1), 96.2 (a-C-1). Anal. Calcd for C104H90O33: C, 66.87;
H, 4.86. Found: C, 66.65; H, 4.99.
Donor 6 (832mg, 0.81mmol) was coupled with acceptor
17 (500mg, 0.62mmol) as described in the general proce-
dure, and the product was purified by chromatography
with 2:1 petroleum ether–EtOAc as the eluent to give
1
18 (706mg, 67%) as a foamy solid: H NMR (CDCl3):
d
7.93–7.20 (m, 35H, 7Ph), 5.71 (dd, 1H,
J3,4 = J4,5 = 9.6Hz, H-4), 5.56 (s, 1H, PhCH), 5.53 (dd,
1H, J2,3 = J3,4 = 9.6Hz, H-3), 5.33 (dd, 1H,
J1,2 = 7.8Hz, J2,3 = 9.6Hz, H-2), 5.24 (s, 1H, PhCH),
5.19 (m, 2H), 4.82 (d, 1H, J1,2 = 4.0Hz, H-1), 4.81–
4.79 (m, 2H), 4.72 (dd, 1H, J1,2 = 3.6Hz, J2,3 = 9.6Hz,
H-2), 4.69 (d, 1H, J1,2 = 7.8Hz, H-1), 4.45 (d, 1H,
J1,2 = 7.6Hz, H-1), 4.38 (dd, 1H, J5,6 = 4.8Hz,
J6,6 = 12Hz, H-6), 4.29 (dd, 1H, J5,6 = 3.6Hz,
J6,6 = 12Hz, H-6), 4.25–4.10 (m, 5H), 3.84–3.65 (m,
6H), 3.65 (dd, 1H), 3.45 (dd, 1H), 3.29 (s, 3H, OCH3),
3.18 (m, 1H), 2.80 (dd, 1H), 1.75 (s, 3H, MeCO), 1.54
(s, 3H, COCH3); 13C NMR (100MHz, CDCl3): d
169.9, 168.7 (2C, 2MeCO), 166.2, 166.0, 165.9, 165.0,
164.9, 164.7, 164.5 (7C, 7PhCO), 101.6, 101.4, 101.3,
100.7, 100.7 (3b-C-1, 2PhCH), 97.2 (a-C-1). Anal. Calcd
for C92H84O30: C, 66.18; H, 5.07. Found: C, 66.47; H,
5.19.
3.12. Allyl 2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!2)]-4,6-O-benzylidene-b-D-glucopyranoside (22)
Compound 22 (2.25g, 95%) was obtained by coupling
the donor 1 (3.0g, 4.05mmol) with the acceptor 21
(0.5g, 1.62mmol) as described in the general procedure:
1
[a]D 5.4 (c 1.0, CHCl3); H NMR (CDCl3): d 8.25–7.21
(m, 45H, 9Ph), 5.82 (dd, 1H, J3,4 = J4,5 = 9.6Hz, H-4),
5.80–5.77 (m, 2H), 5.57–5.52 (m, 3H), 5.50 (s, 1H,
PhCH), 5.41 (dd, 1H), 5.28–5.00 (m, 2H, CH2–
CH@CH2), 4.84 (d, 1H, J1,2 = 7.6Hz, H-1), 4.76 (d,
1H, J1,2 = 8.0Hz, H-1), 4.48 (d, 1H, J1,2 = 7.2Hz, H-
1), 4.26–4.19 (m, 6H), 4.12–3.96 (m, 2H), 3.84 (dd,
1H), 3.82 (dd, 1H), 3.62 (dd, 1H), 3.34 (m, 1H), 2.75–
2.71 (m, 2H); 13C NMR (100MHz, CDCl3): d 165.0,
165.0, 164.8, 164.8, 164.8, 164.7, 164.7, 164.6 (8C,
8PhCO), 100.9, 100.8, 100.6, 100.3 (3b-C-1, PhCH).
Anal. Calcd for C84H72O24: C, 68.85; H, 4.95. Found:
C, 68.70; H, 4.87.
3.11. Methyl 2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!3)-2-O-acetyl-4,6-di-O-benzoyl-b-D-glucopyranosyl-
(1!3)-2,4,6-tri-O-benzoyl-b-D-glucopyranosyl-(1!3)-
4,6-di-O-benzoyl-a-D-glucopyranoside (20)
Compound 18 (700mg, 0.42mmol) was added to 90%
HOAc–H2O (30mL), the mixture was refluxed for 2h,