Y. Ma et al. / Carbohydrate Research 377 (2013) 63–74
73
62.1 (c 2.1, CHCl3); 1H NMR (400 MHz, CDCl3) d 7.39–7.24 (m, 20H,
4 ꢃ C6H5CH2–), 5.92–5.78 (m, 1H, –CH2CHCH2), 5.23 (dd, J = 1.4,
17.0 Hz, 1H, –CH2CHCHH), 5.16 (d, J = 10.4 Hz, 1H, –CH2CHCHH),
5.00 (d, J = 3.6 Hz, 1H, H-10), 4.90 (d, J = 11.2 Hz, 1H, C6H5CHH–),
4.88 (br s, 1H, H-5’), 4.80–4.72 (m, 4H, 3 ꢃ C6H5CHH– + H-1),
4.68 (d, J = 11.6 Hz, 1H, C6H5CHH–), 4.65–4.55 (m, 3H,
5.21 (d, J = 10.4 Hz, 1H, –CH2CHCHH), 4.99–4.97 (m, 2H,
C6H5CHH– + H-5), 4.88–4.86 (m, 2H, C6H5CHH– + H-500), 4.81 (d,
J = 11.2 Hz, 1H, C6H5CHH–), 4.72–4.44 (m, 10H), 4.37–4.34 (m,
3H), 4.21 (br s, 1H), 4.16–4.11 (m, 1H), 4.01 (br s, 1H), 3.94
(dd, J = 3.0, 9.8 Hz, 1H), 3.88 (dd, J = 2.8, 9.2 Hz, 1H), 3.77 (s,
3H), 3.77–3.70 (m, 2H), 3.56 (s, 3H), 3.56–3.53 (m, 1H), 3.50
(dd, J = 2.6, 9.8 Hz, 1H), 3.43 (t, J = 9.4 Hz, 1H, H-4’), 2.43 (br s,
1H, –OH), 1.31 (d, J = 6.0 Hz, 3H, H-6’); 13C NMR (100 MHz,
3 ꢃ C6H5CHH–), 4.39 (br s, 1H, H-4’), 4.16–4.09 (m, 1H,
–
CHHCHCH2), 4.08 (br s, 1H, H-2), 4.00 (dd, J = 3.6, 9.8 Hz, 1H, H-
2’), 3.95–3.82 (m, 3H, –CHHCHCH2+H-3 + H-3’), 3.77–3.67 (m, 1H,
H-5), 3.58 (s, 3H, –CO2CH3), 3.48 (t, J = 9.6 Hz, 1H, H-4), 2.50 (br
s, 1H, -OH), 1.35 (d, J = 6.4 Hz, 3H, H-6); 13C NMR (100 MHz, CDCl3)
d 169.2, 138.5, 138.4, 138.2, 137.8, 133.8, 128.4, 128.32, 128.31,
128.2, 127.93, 127.88, 127.85, 127.6, 127.3, 127.1, 117.2, 96.9,
96.3, 80.2, 79.0, 76.2, 75.2, 74.8, 74.3, 72.7, 72.4, 71.9, 70.1, 68.5,
68.1, 67.8, 52.2, 18.0; HRMS (ESI): calcd for C44H50O11Na [M+Na]+
777.3274, found: 777.3245.
CDCl3)
d 169.3, 168.3, 138.9, 138.6, 138.41, 138.37, 137.8,
137.6, 133.9, 128.4–127.2, 117.6, 102.8, 98.0, 96.2, 80.8,
79.9, 78.7, 78.4, 76.2, 75.1, 74.61, 74.56, 74.1, 73.7, 73.2, 72.7,
72.24, 72.16, 71.8, 70.6, 70.0, 68.5, 68.4, 52.5, 52.1, 18.0; HRMS
+
(ESI) calcd for
1147.4662.
C
65H72O17Na [M+Na
]
1147.4699, found:
3.1.29. Methyl (methyl 4-O-acetyl-2,3-di-O-benzyl-
pyranosyluronate)-(1?2)-3, 4-di-O-benzyl- -rhamnopyra-
nosyl-(1?4)-methyl 2,3-di-O-benzyl- -galacto pyranosy-
luronate-(1?2)-3,4-di-O-benzyl- -rhamnopyranosyl-(1?4)-
(allyl 2,3-di-O-benzyl-b- -galactopyranosyl)uronate (36)
a-D-galacto-
a-L
3.1.26. Methyl 4-O-acetyl-2,3-di-O-benzyl-
syluronate-(1?4)-methyl 2,3-di-O-benzyl-
luronate-(1?2)-allyl 3,4-di-O-benzyl- -rhamnopyranoside (34)
Compound 34 (89.3 mg, 99%, /b = 6.6/1) was prepared from
a
a
-
D
-galactopyrano-
a-D
-D-galactopyranosy-
a-L
a-L
D
a
To a solution of 26 (163 mg, 0.18 mmol) in anhydrous toluene
(5.0 mL), 35 (123 mg, 0.11 mmol) and 4 Å MS (500 mg) were
added. After stirring vigorously at rt for 30 min, the mixture
was cooled to ꢀ70 °C and TBSOTf (0.05 M in CH2Cl2, 0.7 mL)
was added slowly. After stirring for 1 h, the mixture was allowed
to warm to ꢀ50 °C and kept for 3 h. When TLC showed comple-
tion of the reaction, Et3N was added to quench the reaction. The
resulting mixture was diluted with CH2Cl2, filtered through a pad
of Celite, and concentrated in vacuo. The residue was purified by
column chromatography on silica gel (toluene/ethyl acetate,
33 (61 mg, 0.077 mmol) and 7 (69 mg, 0.11 mmol) following a
procedure similar to that for 29 ? 27. ½a D25
ꢂ
66.0 (c 0.8, CHCl3);
1H NMR (400 MHz, CDCl3) d 7.43–7.20 (m, 30H, 6 ꢃ C6H5CH2–),
5.92–5.80 (m, 1H, –CH2CHCH2), 5.75 (br s, 1H, H-400), 5.24 (d,
J = 17.2 Hz, 1H, –CH2CHCHH), 5.18 (d, J = 10.8 Hz, 1H,
–
CH2CHCHH), 5.09 (br s, 1H, H-500), 5.07 (d, J = 3.2 Hz, 2H, H-
1’ + H-100), 4.84–4.80 (m, 3H), 4.77–4.73 (m, 3H), 4.71–4.65 (m,
4H), 4.57 (d, J = 1.2 Hz, 1H), 4.54 (d, J = 4.0 Hz, 1H), 4.50 (br s,
1H), 4.42 (d, J = 10.4 Hz, 1H), 4.17–4.08 (m, 2H), 4.01–3.84 (m,
5H), 3.76–3.67 (m, 2H), 3.44 (s, 3H), 3.40 (t, J = 9.6 Hz, 1H), 3.28
(s, 3H), 1.98 (s, 3H), 1.34 (d, J = 6.0 Hz, 3H, H-6); 13C NMR
(100 MHz, CDCl3) d 169.8, 168.5, 168.4, 138.4, 138.32, 138.29,
138.0, 137.9, 133.8, 128.3–126.7, 117.1, 99.6, 96.6, 96.2, 80.2,
78.8, 76.6, 76.1, 75.9, 75.2, 74.0, 73.5, 73.3, 73.1, 72.1, 72.02,
71.95, 71.5, 70.5, 69.6, 68.8, 68.1, 67.7, 52.0, 51.8, 20.6, 17.9;
HRMS (ESI) calcd for C67H74O18Na [M+Na]+ 1189.4747, found:
1189.4767.
10:1) to provide 36 (201 mg, 99%) as a colorless syrup: ½a D25
ꢂ
92.3 (c 0.9, CHCl3); 1H NMR (300 MHz, CDCl3) d 7.41–7.16 (m,
50H, 10 ꢃ C6H5CH2–), 6.02–5.86 (m, 1H, –CH2CHCH2), 5.80 (br
s, 1H, H-40000), 5.37–5.29 (m, 3H, –CH2CHCHH + H-100 + H-10000),
5.20 (d, J = 10.5 Hz, 1H, –CH2CHCHH), 5.01–4.94 (m, 4H), 4.87–
4.72 (m, 5H), 4.66–4.34 (m, 19H), 4.19–4.09 (m, 3H), 4.03–3.98
(m, 2H), 3.93 (dd, J = 2.8, 13.6 Hz, 1H), 3.86–3.68 (m, 8H),
3.55–3.32 (m, 11H), 2.07 (s, 3H), 1.31 (d, J = 7.6 Hz, 3H), 1.28
(d, J = 8.0 Hz, 3H); 13C NMR (100 MHz, CDCl3) d 169.9, 168.9,
168.4, 168.3, 138.81, 138.76, 138.6, 138.43, 138.40, 137.8,
137.6, 133.8, 128.4–127.0, 117.6, 102.7, 97.8, 97.7, 96.7, 96.1,
80.7, 80.0, 79.8, 79.0, 78.7, 78.6, 77.2, 75.3, 74.8, 74.7, 74.6,
74.3, 74.2, 73.8, 73.7, 73.1, 72.6, 72.4, 72.1, 72.0, 71.8, 71.6,
70.6, 69.2, 68.8, 68.6, 68.5, 52.5, 52.10, 52.07, 20.8, 18.1, 18.0;
HRMS (ESI) calcd for C108H118O28 Na [M+Na]+ 1885.7681, found:
1885.7702.
3.1.27. Propyl
a-D
-galactopyranosyluronic acid-(1?4)-
a-D-
galactopyranosyluronic acid-(1?2)-
a
-L
-rhamnopyranoside (3)
Compound 3 (15.4 mg, 79% over two steps) was prepared from
34 (42 mg, 0.036 mmol) following a procedure similar to that for
31?2. ½a 2D5
ꢂ
68.8 (c 0.3, MeOH); 1H NMR (400 MHz, D2O) d 5.07
(m, 2H, H-1’ + H-100), 4.91 (br s, 1H), 4.75 (br s, 1H), 4.67 (br s,
1H), 4.43 (d, J = 2.0 Hz, 1H), 4.27 (d, J = 2.0 Hz, 1H), 4.08 (dd,
J = 3.0, 10.6 Hz, 1H), 3.99(d, J = 2.8 Hz, 1H), 3.91(dd, J = 3.2 Hz,
1H), 3.88–3.83 (m, 2H), 3.75–3.65 (m, 3H), 3.53–3.48 (m, 2H),
1.60–1.54 (m, 2H), 1.30 (d, J = 6.4 Hz, 3H, H-6), 0.91 (t, J = 7.4 Hz,
3H); 13C NMR (100 MHz, D2O) d 176.1, 175.3, 99.1, 97.6, 97.2,
78.1, 76.0, 72.3, 71.8, 71.2, 70.8, 69.8, 69.7, 69.6, 68.8, 68.7, 68.3,
67.9, 22.0, 16.5, 9.8; HRMS (ESI): calcd for C21H33O17 [M-H]ꢀ
557.1721, found: 557.1723.
3.1.30.
ranosyl-(1?4)-
rhamnopyranosyl-(1?4)-
Pentasaccharide 4 (24 mg, 82% over two steps) as a white so-
a-
D
-Galactopyranosyluronic acid-(1?2)-
-galactopyranosyluronic acid-(1?2)-
-galactopyranosiduronic acid (4)
a-L-rhamnopy-
a-
D
a-L-
a
-D
lid was prepared from 36 (62 mg, 0.033 mmol) following
a
procedure similar to that for 31?2. ½a D25
ꢂ
42.1 (c 0.9, MeOH);
1H NMR (400 MHz, D2O) d 5.25 (br s, 1H), 5.23 (br s, 1H), 5.04
(br s, 2H), 4.89 (br s, 1H), 4.85 (br s, 1H), 4.44–4.42 (m, 2H),
4.36 (br s, 1H), 4.33 (br s, 1H), 4.25 (br s, 1H), 4.16–4.10 (m,
3H), 4.02–3.82 (m, 8H), 3.76–3.68 (m, 2H), 3.64–3.50 (m, 2H),
3.47–3.40 (m, 2H), 1.70–1.59 (m, 2H), 1.26 (d, J = 6.0 Hz, 6H),
0.93 (t, J = 7.4 Hz, 3H); 13C NMR (100 MHz, D2O) d 102.8, 99.5,
98.3, 78.2, 77.7, 76.93, 76.89, 76.84, 74.2, 73.9, 72.7, 72.4, 72.1,
71.0, 70.9, 70.3, 69.9, 69.6, 68.5, 68.4, 22.7, 17.1, 10.2;
3.1.28. Methyl (methyl 2,3-di-O-benzyl-
a-D-
galactopyranosyluronate)-(1?2)-(3,4-di-O-benzyl-
a-L-
rhamnopyranosyl)-(1?4)-(allyl 2,3-di-O-benzyl-b-D-
galactopyranosyl)uronate (35)
Compound 35 (123 mg, 87%) was prepared from 27 (150 mg,
0.13 mmol) following a procedure similar to that for 28?29.
½
a 2D5 70.8 (c 6.2, CHCl3); 1H NMR (400 MHz, CDCl3) d 7.39–7.17
(m, 30H, 6 ꢃ C6H5CH2–), 6.03–5.87 (m, 1H, –CH2CHCH2), 5.35
ꢂ
HRMS (ESI) calcd for
879.2623.
C
33H52O27 [M-H]ꢀ 879.2663, found:
(br s, 1H, H-100), 5.34 (dq, J = 17.4, 1.5 Hz, 1H, –CH2CHCHH),