ORDER
REPRINTS
Synthesis of Trisaccharide of Incanoside from Caryopteris incana
521
(m, 1H, H-5), 2.17 (s, 3H, CH3CO), 2.13 (s, 3H, CH3CO), 0.72 (d, 3H,
6.09 Hz, H-60) ppm.
Phenyl 3,4-di-O-benzoyl-a-L-rhamnopyranosyl-(1 ! 3)-2-O-acetyl-
4,6-O-benzylidene-1-thio-b-D-glucopyranoside (11). To a solution of 10
(1.6 g, 2.0 mmol) in 25 mL THF was added 3.0 equiv of 85% hydrazine
hydrate (0.38 mL). The mixture was stirred at room temperature for 11 h, then
quenched by the addition of H2O (20 mL) and extracted with CH2Cl2. The
combined organic layers were washed with brine, dried over MgSO4, filtered
and concentrated under reduced pressure. The crude product was subject to
column chromatography on silica gel with petroleum ether/ethyl acetate
(3 : 1) as the eluent to give 11 (1.12 g, 73.8%). m.p. 170.2–172.58C; 1H NMR
d 7.95–7.17 (m, 20H, Bz-H and Ph-H), 5.61 (s, 1H, PhCH), 5.53 (dd, 1H,
H-30), 5.41 (t, 1H, H-40), 5.09 (t, 1H, H-2), 5.00 (s, 1H, H-10), 4.74 (dd, 1H,
10.09 Hz, H-1), 4.44–4.40 (dd, 1H, H-6a), 4.37–4.34 (m, 1H, H-50), 4.15
(br, 1H, H-20), 4.08 (t, 1H, H-6b), 3.82 (t, 1H, H-4), 3.71 (t, 1H, H-3), 3.60–
3.56 (m, 1H, H-5), 2.14 (s, 3H, CH3CO), 0.80 (d, 3H, 6.15 Hz, H-60). Anal.
Calcd for C41H40O12S: C, 65.07; H, 5.23; S, 4.24. Found: C, 64.38; H, 5.33;
S, 4.17. MS(ESI): 779 ([M þ Na]þ).
Phenyl 2,3,4,6-tetra-O-acetyl-b-D-glucopyranosyl-(1 ! 2)- 3,4-di-O-
benzoyl-a-L-rhamnopyranosyl-(1 ! 3)-2-O-acetyl-4,6-O-benzylidene-1-
thio-b-D-glucopyrano side (12). The disaccharide acceptor 11 (151 mg,
0.2 mmol) and glucosyl donor 5 (128 mg, 0.26 mmol) were dried under high
vacuum for 2–3 h, then dissolved in dry CH2Cl2 (15 mL) and 24 mL of a 0.2N
.
solution of BF3 OEt2 was added dropwise at 2308C under N2. The reaction
mixture was stirred for 3 h, and then neutralized with triethylamine, concen-
trated under reduced pressure to dryness. Further purification by column
chromatography (1/1.5 petroleum ether/ethyl acetate as eluent) gave 12
1
(197 mg, 91%) as a colorless solid. m.p. 264.3–275.88C; H NMR d 7.95–
7.19 (m, 20H, Bz-H and Ph-H), 5.61 (s, 1H, PhCH), 5.53 (dd, 1H, H-30), 5.45
(t, 1H, H-300), 5.40 (br, 2H, H-10 and H-40), 5.12–5.10 (m, 2H, H-2 and H-200),
4.62 (dd, 1H, 9.74 Hz, H-1), 4.44–4.40 (m, 2H, H-6a and H-400), 4.33 (br, 1H,
H-20), 4.23–4.20 (m, 2H, H-50 and H-6a00), 4.08 (dd, 1H, 6.74 Hz, H-100), 4.01
(t, 1H, H-6b), 3.87–3.80 (m, 2H, H-6b00 and H-4), 3.63 (t, 1H, H-3), 3.60–3.56
(m, 2H, H-500 and H-5), 2.11–2.00 (5s, 15H, 5CH3CO), 0.98 (d, 3H, 6.70 Hz,
H-60). HRMS(ESI): Calcd for C56H60O20S: 1083.3320([M-H]þ). Found:
1083.3344([M-H]þ).
ACKNOWLEDGMENTS
The work was supported by The National Natural Science Foundation of
China (No. 20272051) and by The Teaching and Research Award Program