X.-Q. Shen et al. / Carbohydrate Research 344 (2009) 2063–2068
2067
reaction mixture was stirred for 30 min at the same temperature.
Then the mixture was stirred for 1.5 h during which time it was
gradually warmed to ambient temperature. The reaction was
quenched with Et3N and filtered. The filtrates were concentrated
in vacuo to give a residue, which was purified by column chroma-
tography (10:1 petroleum ether–EtOAc) to afford 12 as a colorless
5.35 (m, 2H, H-30, H-Z), 5.23–5.25 (m, 1H, H-E), 5.15 (dd, 1H,
J = 1.6, 3.2 Hz, H-2), 4.99 (t, 1H, J = 4.0 Hz, H-20), 4.75 (d, 1H,
J = 8.0 Hz, H-10), 4.72 (d, 1H, J = 1.2 Hz, H-1), 4.34 (dd, 1H, J = 5.2,
10.4 Hz, H-40), 4.14–4.19 (m, 1H, CH2–CH@CH2), 3.97–4.02 (m,
1H, CH2–CH@CH2), 3.92 (dd, 1H, J = 3.2, 9.6 Hz, H-3), 3.63 (t, 1H,
J = 9.2 Hz, H-4), 3.60–3.74 (m, 3H, H-50, H-6a0, H-6b0), 3.49–3.55
(m, 1H, H-5), 2.58–2.65 (m, 1H, COCH(CH3)2), 2.41 (d, 1H,
J = 2.4 Hz, OH), 2.08 (s, 3H, COCH3), 2.06 (s, 3H, COCH3), 1.35 (d,
3H, J = 6.0 Hz, H-6), 1.20 (d, 3H, J = 7.2 Hz, COCH(CH3)2), 1.18 (d,
3H, J = 7.2 Hz, COCH(CH3)2); 13C NMR (100 MHz, CDCl3): d 176.1
(COCH(CH3)2), 170.2 (COCH3), 170.0 (COCH3), 136.7, 133.4, 129.1,
128.2, 126.1, 118.0, 101.6, 101.5, 96.6, 79.7, 78.1, 72.7, 71.5, 70.3,
68.4, 68.3, 67.7, 66.3, 33.9, 20.8, 20.7, 19.1, 18.7, 17.6. ESIMS: calcd
for C30H40O13 [M+Na]+, 631.2361, found m/z 631.2363.
syrup (64 mg, 82%). ½a D20
ꢁ
ꢀ0.017 (c 1.2, CHCl3); 1H NMR (400 MHz,
CDCl3): d 7.41–7.45 (m, 2H, PhH), 7.35–7.37 (m, 3H, PhH), 7.26–
7.31 (m, 5H, PhH of Bn), 6.04 (d, 1H, J = 5.6 Hz, H-10), 5.86–5.96
(m, 1H, CH2–CH@CH2), 5.72 (t, 1H, J = 2.4 Hz, H-200), 5.53 (dd, 1H,
J = 4.8, 9.6 Hz, H-30), 5.48 (s, 1H, PhCH), 5.30 (ddd, 1H, J = 1.2, 3.2,
16.6 Hz, H-Z), 5.25 (ddd, 1H, J = 1.2, 2.8, 10.4 Hz, H-E), 5.14 (dd,
1H, J = 2.0, 3.2 Hz, H-2), 5.08 (d, 1H, J = 2.0 Hz, H-100), 5.02 (t, 1H,
J = 10.0 Hz, H-400), 4.72 (d, 1H, J = 2.0 Hz, H-1), 4.67 (d, 1H,
J = 11.6 Hz, PhCH2), 4.52 (t, 1H, J = 5.6 Hz, H-20), 4.41 (d, 1H,
J = 11.6 Hz, PhCH2), 4.27 (dd, 1H, J = 5.6, 10.4 Hz, H-40), 4.16–4.19
(m, 1H, CH2–CH@CH2), 4.15 (d, 2H, J = 0.8 Hz, COCH2Cl), 4.14 (d,
2H, J = 1.6 Hz, COCH2Cl), 3.98–4.04 (m, 1H, CH2–CH@CH2), 3.72–
3.93 (m, 7H, H-3, H-300, H-5, H-50, H-500, H-6a0, H-6b0), 3.63 (t, 1H,
J = 9.6 Hz, H-4), 2.56–2.65 (m, 1H, COCH(CH3)2), 2.47–2.55 (m,
1H, COCH(CH3)2), 1.33 (d, 3H, J = 6.4 Hz, H-600), 1.19 (d, 3H,
J = 7.2 Hz, H-6), 1.18 (d, 3H, J = 6.4 Hz, COCH(CH3)2), 1.17 (d, 3H,
J = 7.2 Hz, COCH(CH3)2), 1.16 (d, 3H, J = 6.4 Hz, COCH(CH3)2), 1.14
(d, 3H, J = 7.2 Hz, COCH(CH3)2); 13C NMR (100 Hz, CDCl3): d 176.3
(COCH(CH3)2), 166.5 (COCH2Cl), 133.6, 129.2, 128.5, 128.3, 128.2,
127.7, 127.5, 126.2, 120.3, 117.6, 110.5, 101.6, 100.1, 99.1, 96.1,
79.9, 77.8, 77.3, 77.0, 76.7, 76.3, 75.1, 75.0, 72.4, 71.8, 71.5, 71.4,
70.3, 67.6, 67.4, 63.0, 45.9, 40.8, 40.6, 34.0, 33.9, 29.6, 19.1, 19.0,
18.8, 18.7, 18.2, 17.2. ESIMS: calcd for C49H61O19Cl3 [M+Na]+,
1081.2765, found m/z 1081.2789.
1.10. Allyl 2,3-di-O-acetyl-4,6-O-benzylidene-b-D-glucopyran-
osyl-(1?3)-2-O-chloroacetyl-3-O- benzyl-4-O-isobutyryl-
a-L-
rhamnopyranosyl-(1?4)-2-O-isobutyryl-a-L-rhamnopyrano-
side (16)
Trisaccharide glycoside 16 was obtained as a colorless syrup
from 3 (73.2 mg, 0.13 mmol) and 15 (43 mg, 0.071 mmol) as de-
scribed for preparation of 12, yielding 63 mg (88%). ½a D20
ꢀ37.4 (c
ꢁ
1.0, CHCl3); 1H NMR (400 MHz, CDCl3): d 7.44–7.47 (m, 2H, PhH),
7.34–7.39 (m, 3H, PhH), 7.26–7.32 (m, 5H, PhH of Bn), 5.88–5.98
(m, 1H, CH2–CH@CH2), 5.49 (s, 1H, PhCH), 5.48 (dd, 1H, J = 1.6,
3.2 Hz, H-200), 5.34 (d, 1H, J = 2.0 Hz, H-100), 5.21–5.34 (m, 3H,
H-Z, H-E, H-30), 5.12 (dd, 1H, J = 1.6, 3.2 Hz, H-2), 5.04 (t, 1H,
J = 9.6 Hz, H-20), 4.91 (t, 1H, J = 7.6 Hz, H-400), 4.82 (d,
1H, J = 7.6 Hz, H-10), 4.70 (d, 1H, J = 1.6 Hz, H-1), 4.68 (d, 1H,
J = 11.6 Hz, PhCH2), 4.45 (d, 1H, J = 11.6 Hz, PhCH2), 4.36 (dd,
1H, J = 5.2, 10.4 Hz, H-40), 4.25 (s, 2H, COCH2Cl), 4.09–4.23 (m,
3H, H-300, CH2–CH@CH2, H-4), 3.98–4.03 (m, 1H, CH2–CH@CH2),
3.83–3.89 (m, 1H, H-3), 3.69–3.82 (m, 4H, H-50, H-500, H-6a0, H-
6b0), 3.56–3.62 (m, 1H, H-5), 2.58–2.65 (m, 1H, COCH(CH3)2),
2.48–2.55 (m, 1H, COCH(CH3)2), 2.05 (s, 3H, COCH3), 2.01 (s, 3H,
COCH3), 1.32 (d, 3H, J = 5.2 Hz, H-6), 1.20 (d, 3H, J = 7.2 Hz, H-600),
1.18 (d, 3H, J = 6.4 Hz, COCH(CH3)2), 1.17 (d, 3H, J = 7.2 Hz,
COCH(CH3)2), 1.16 (d, 3H, J = 7.2 Hz, COCH(CH3)2), 1.14 (d, 3H,
J = 7.2 Hz, COCH(CH3)2); 13C NMR (100 MHz, CDCl3): d 176.2
(COCH(CH3)2), 176.0 (COCH(CH3)2), 170.1 (COCH3), 169.3 (COCH3),
167.2 (COCH2Cl), 137.4, 136.8, 133.5, 129.1, 128.3, 128.2, 127.7,
126.2, 117.9, 101.5, 99.8, 97.0, 96.4, 78.0, 77.4, 75.8, 74.6, 72.9,
71.7, 71.6, 71.6, 71.5, 70.4, 68.5, 67.6, 66.4, 66.3, 40.7, 34.0, 33.9,
20.8, 20.5, 19.1, 19.0, 18.8, 18.6, 17.3; ESIMS: calcd for C49H63O19Cl
[M+Na]+, 1013.3544, found m/z 1013.3553.
1.8. Allyl 2,3-di-O-acetyl-4,6-O-benzylidene-b-D-glucopyran-
osyl-(1?3)-2-O-isobutyryl-4-O-p- methoxybenzyl-L-rhamno-
pyranoside (14)
Disaccharide 14 was obtained as a colorless syrup from 2
(92.8 mg, 0.234 mmol) and 13 (210 mg, 0.423 mmol) as described
for the preparation of 10, yielding 122.3 mg (72%). ½a D20
ꢀ51.7 (c
ꢁ
1.0, CHCl3); 1H NMR (400 MHz, CDCl3): d 7.42–7.45 (m, 2H, PhH),
7.35–7.39 (m, 3H, PhH), 7.29, 6.89 (each 2H, AA0BB0, J = 8.8 Hz,
PhH of PMB), 5.82–5.93 (m, 1H, CH2–CH@CH2), 5.49 (s, 1H, Ph
CH), 5.25–5.31 (m, 2H, H-Z, H-30), 5.18–5.21 (m, 1H, H-E), 5.18
(dd, 1H, J = 1.6, 2.8 Hz, H-2), 5.05 (d, 1H, J = 7.6 Hz, H-10), 5.04 (t,
1H, J = 7.6 Hz, H-20), 4.72 (d, 1H, J = 10.8 Hz, PhCH2), 4.69 (d, 1H,
J = 1.2 Hz, H-1), 4.68 (d, 1H, J = 10.8 Hz, PhCH2), 4.34 (dd, 1H,
J = 4.8, 10.4 Hz, H-40), 4.09–4.17 (m, 2H, H-3, CH2–CH@CH2),
3.94–3.98 (m, 1H, CH2–CH@CH2), 3.81 (s, 3H, PhOCH3), 3.66–3.77
(m, 3H, H-50, H-6a0, H-6b0), 3.47–3.53 (m, 1H, H-5), 3.43 (t, 1H,
J = 8.8 Hz, H-4), 2.60–2.67 (m, 1H, COCH(CH3)2), 2.04 (s, 3H,
COCH3), 1.86 (s, 3H, COCH3), 1.26 (d, 3H, J = 10.4 Hz, H-6), 1.23
(d, 3H, J = 7.2 Hz, COCH(CH3)2), 1.19 (d, 3H, J = 7.2 Hz,
COCH(CH3)2); 13C NMR (50 MHz, CDCl3): d 176.1 (COCH(CH3)2),
170.1 (COCH3), 169.5 (COCH3), 159.4, 136.8, 133.5, 130.1, 129.7,
129.4, 129.1, 128.2, 126.1, 117.8, 117.4, 113.9, 101.4, 101.2, 96.4,
79.4, 78.2, 78.1, 74.6, 72.7, 72.2, 71.5, 68.5, 68.1, 67.5, 66.2, 55.2,
33.9, 20.7, 20.6, 19.2, 18.7, 17.8. ESIMS: calcd for C38H48O14
[M+Na]+, 751.2936, found m/z 751.2921.
1.11. 2,3-Di-O-acetyl-4,6-O-benzylidene-b-
(1?3)-2-O-chloroacetyl-3-O-benzyl-4-isobutyryl-
D
-glucopyranosyl-
-rhamno-
pyranosyl-(1?4)-2-O-isobutyryl-a-L-rhamnopyranosyl trichlo-
a-L
roacetimidate (1)
The target trisaccharide imidate 1 was obtained as a colorless
syrup from 16 (67 mg, 0.092 mmol) as described for preparation
of 3, yielding 45 mg (65% over two steps). ½a D20
ꢀ30.5 (c 1.0, CHCl3);
ꢁ
1H NMR (400 MHz, CDCl3): d 8.73 (s, 1H, NH), 7.43–7.44 (m, 2H,
PhH), 7.35–7.36 (m, 3H, PhH), 7.25–7.32 (m, 5H, PhH of Bn), 6.13
(d, 1H, J = 1.6 Hz, H-1), 5.49 (s, 1H, PhCH), 5.48 (dd, 1H, J = 1.6,
3.2 Hz, H-200), 5.33 (d, 1H, J = 2.0 Hz, H-100), 5.30 (dd, 1H, J = 1.6,
3.2 Hz, H-2), 5.25 (t, 1H, J = 8.8 Hz, H-30), 5.04 (t, 1H, J = 10.0 Hz,
H-20), 4.92 (t, 1H, J = 8.4 Hz, H-400), 4.83 (d, 1H, J = 7.2 Hz, H-10),
4.67 (d, 1H, J = 10.6 Hz, PhCH2), 4.48 (d, 1H, J = 10.6 Hz, PhCH2),
4.24 (s, 2H, COCH2Cl), 4.24–4.26 (m, 2H, H-40, H-4), 3.72–3.92 (m,
6H, H-300, H-3, H-50, H-500, H-6a0, H-6b0), 3.60–3.64 (m, 1H, H-5),
2.61–2.66 (m, 1H, COCH(CH3)2), 2.48–2.53 (m, 1H, COCH(CH3)2),
2.05 (s, 3H, COCH3), 2.01 (s, 3H, COCH3), 1.35 (d, 3H, J = 6.0 Hz,
1.9. Allyl 2,3-di-O-acetyl-4,6-O-benzylidene-b-
D-glucopyr-
anosyl-(1?3)-2-O-isobutyryl- -rhamnopyranoside (15)
a-L
Disaccharide alcohol 15 was obtained as a colorless syrup from
14 (67 mg, 0.092 mmol) as described for the preparation of 11,
yielding 43 mg (77%).
(400 MHz, CDCl3): d 7.42–7.45 (m, 2H, PhH), 7.35–7.39 (m, 3H,
½
a 2D0
ꢁ
ꢀ32.6 (c 1.0, CHCl3); 1H NMR
PhH), 5.87–5.97 (m, 1H, CH2–CH@CH2), 5.48 (s, 1H, PhCH), 5.29–