Shark Cartilage Chondroitin Sulfate D-Related Tetra- and Hexasaccharide Methyl Glycosides
1H NMR (250 MHz, CDCl3): δ ϭ 8.05Ϫ6.82 (m, 19 H, ArH), 6.94 C-3, C-4, C-5; 2 CH2Ph), 62.83 (GalN C-6), 53.22 (COOCH3),
FULL PAPER
(d, J ϭ 6.6 Hz, 1 H, NH), 5.45 (dd, J1,2 ϭ 7.8, J2,3 ϭ 9.3 Hz, 1 H,
GlcA 2-H), 5.35 (d, J1,2 ϭ 8.4 Hz, 1 H, GalN 1-H), 5.33 (dd, J3,4 ϭ
9.0, J4,5 ϭ 9.9 Hz, 1 H, GlcA 4-H), 4.92, 4.61 (2 ABq, 4 H, 2
50.87 (GalN C-2), 40.34 (CH2Cl).
β-Anomer: This was obtained from the mother liquors of crystal-
lization of the α-anomer, still containing ഠ 20% of α-anomer (0.7 g,
14%). 1H NMR (250 MHz, CDCl3), selected data: δ ϭ 8.62 (s, 1
H, CϭNH), 8.10Ϫ7.10 (m, 20 H, 4 Ph), 6.89 (d, J ϭ 7.0 Hz, 1 H,
NH), 6.28 (d, J1,2 ϭ 7.8 Hz, 1 H, GalN 1-H), 5.46 (dd, J1,2 ϭ 7.8,
J2,3 ϭ 9.1 Hz, 1 H, GlcA 2-H), 5.32 (dd, J3,4 ϭ 9.0, J4,5 ϭ 9.9 Hz,
1 H, GlcA 4-H), 4.91, 4.60 (2 ABq, 4 H, 2 CH2Ph), 4.87 (dd, J2,3 ϭ
10.4, J3,4 ϭ 2.8 Hz, 1 H, GalN 3-H), 4.86 (d, 1 H, GlcA 1-H), 4.51
(dd, J5,6a ϭ 6.1, J6a,6b ϭ 11.0 Hz, 1 H, GalN 6a-H), 4.35 (dd,
J5,6b ϭ 7.5 Hz, 1 H, GalN 6b-H), 4.29 (dd, J4,5 ϭ 0.8 Hz, 1 H,
GalN 4-H), 4.09 (d, 1 H, GlcA 5-H), 4.05 (m, 1 H, GalN 5-H),
3.89 (t, 1 H, GlcA 3-H), 3.84 (ABq, 2 H, COCH2Cl), 3.64 (s, 3
H, COOCH3).
CH2Ph), 4.82 (d, 1 H, GlcA 1-H), 4.80 (dd, J2,3 ϭ 10.1, J3,4
ϭ
3.0 Hz, 1 H, GalN 3-H), 4.11 (dd, J4,5 ϭ 0.8 Hz, 1 H, GalN 4-H),
4.09 (d, 1 H, GlcA 5-H), 3.90 (dd, 1 H, GlcA 3-H), 3.87 (ABq, 2
H, COCH2Cl), 3.77 (s, 3 H, COOCH3), 3.75 (m, 2 H, GalN 2-H,
6a-H), 3.72 (s, 3 H, OCH3), 3.58 (dd, J5,6a ϭ 5.4, J5,6b ϭ 6.4 Hz, 1
H, GalN 5-H), 3.47 (m, J6a,6b ϭ 12.0, J6b,OH ϭ 4.1 Hz, 1 H, GalN
6b-H), 2.40 (dd, J6a,OH ϭ 8.2 Hz, 1 H, GalN 6-OH). MS (IS):
m/z ϭ 999 [Mϩ ϩ NH4] for 35Cl. C45H45Cl4NO15·H2O (999.66):
calcd. C 54.07, H 4.74, N 1.40; found C 54.18, H 4.64, N 1.50.
4-Methoxyphenyl (Methyl 2-O-benzoyl-3-O-benzyl-4-O-chloroacet-
yl-β-
D
-glucopyranosyluronate)-(1Ǟ3)-6-O-benzoyl-4-O-benzyl-2-
-galactopyranoside (14): Benzoyl
deoxy-2-trichloroacetamido-β-
D
Methyl (Methyl 2-O-benzoyl-3-O-benzyl-4-O-chloroacetyl-β-
glucopyranosyluronate)-(1Ǟ3)-6-O-benzoyl-4-O-benzyl-2-deoxy-2-
trichloroacetamido-β- -galactopyranoside (16): A mixture of imid-
D-
chloride (0.6 mL, 5 mmol) was added at 0 °C to a solution of alco-
hol 13 (2.4 g, 2.5 mmol) in CH2Cl2 (50 mL) and pyridine (1 mL),
and the mixture was stirred for 30 min at this temperature. Meth-
anol (0.5 mL) was then added, and the mixture was diluted with
CH2Cl2 (100 mL), washed with water, satd. aq. NaHCO3, and
water, dried (MgSO4), and concentrated. The residue was crystal-
lized from EtOAc to give ester 14 (2.4 g, 89%). M.p. 242Ϫ244 °C.
[α]2D2 ϭ Ϫ18 (c ϭ 1, chloroform). 1H NMR (250 MHz, CDCl3):
δ ϭ 8.10Ϫ6.80 (m, 24 H, ArH), 6.95 (d, J ϭ 6.4 Hz, 1 H, NH),
5.45 (dd, J1,2 ϭ 7.8, J2,3 ϭ 9.3 Hz, 1 H, GlcA 2-H), 5.32 (dd, J3,4 ϭ
9.2, J4,5 ϭ 10.0 Hz, 1 H, GlcA 4-H), 5.31 (d, J1,2 ϭ 8.2 Hz, 1 H,
GalN 1-H), 4.94, 4.61 (2 ABq, 4 H, 2 CH2Ph), 4.84 (d, 1 H, GlcA
1-H), 4.83 (dd, J2,3 ϭ 10.9, J3,4 ϭ 0.8 Hz, 1 H, GalN 4-H), 4.50
(dd, J5,6a ϭ 5.6, J6a,6b ϭ 11.1 Hz, 1 H, GalN 6a-H), 4.30 (dd,
J5,6b ϭ 7.3 Hz, 1 H, GalN 6b-H), 4.24 (dd, J4,5 ϭ 0.8 Hz, 1 H,
GalN 4-H), 4.08 (d, 1 H, GlcA 5-H), 3.90 (t, 1 H, GlcA 3-H), 3.85
(m, 2 H, GalN 2-H, 5-H), 3.84 (ABq, 2 H, COCH2Cl), 3.69 (s, 3
D
ates 15α,β (3 g, 2.7 mmol), anhydrous MeOH (0.54 mL,
˚
13.5 mmol), and powdered 3-A molecular sieves (2 g) in anhydrous
CH2Cl2 (20 mL) was stirred for 1 h at room temperature under dry
argon. A solution of TMSOTf in toluene (1 , 0.4 mL) was then
added, and the mixture was stirred for 30 min at this temperature.
Triethylamine (0.3 mL) was added, and the mixture was diluted
with CH2Cl2 (100 mL), filtered, washed with satd. aq. NaHCO3
and water, dried (MgSO4), and concentrated. Crystallization of the
residue from EtOAc/petroleum ether gave methyl glycoside 16
(2.3 g, 86%). M.p. 204Ϫ205 °C. [α]2D2 ϭ Ϫ10 (c ϭ 1, chloroform).
1H NMR (250 MHz, CDCl3): δ ϭ 8.18Ϫ7.10 (m, 20 H, 4 Ph), 6.79
(d, J ϭ 6.6 Hz, 1 H, NH), 5.42 (dd, J1,2 ϭ 7.9, J2,3 ϭ 9.4 Hz, 1 H,
GlcA 2-H), 5.31 (dd, J3,4 ϭ 9.0, J4,5 ϭ 10.0 Hz, 1 H, GlcA 4-H),
4.90, 4.60 (2 ABq, 4 H, 2 CH2Ph), 4.82 (d, 1 H, GlcA 1-H), 4.81
(d, J1,2 ϭ 8.2 Hz, 1 H, GalN 1-H), 4.78 (dd, J2,3 ϭ 11.3, J3,4
ϭ
H, COOCH3), 3.67 (s, 3 H, OCH3). MS (IS): m/z ϭ 1103 [Mϩ
ϩ
2.9 Hz, 1 H, GalN 3-H), 4.49 (dd, J5,6a ϭ 6.3, J6a,6b ϭ 11.1 Hz, 1
H, GalN 6a-H), 4.27 (dd, J5,6b ϭ 6.8 Hz, 1 H, GalN 6b-H), 4.20
(dd, J4,5 ϭ 0.8 Hz, 1 H, GalN 4-H), 4.06 (d, 1 H, GlcA 5-H), 3.89
(dd, 1 H, GlcA 3-H), 3.86 (ABq, 2 H, COCH2Cl), 3.85 (m, 1 H,
GalN 5-H), 3.63 (s, 3 H, COOCH3), 3.57 (m, 1 H, GalN 2-H), 3.44
NH4], 962 [Mϩ ϪOC6H4OCH3] for 35Cl.Ϫ C52H49Cl4NO16
(1085.75): calcd. C 57.52, H 4.55, N 1.29; found C 57.49, H 4.55,
N 1.34.
(Methyl 2-O-Benzoyl-3-O-benzyl-4-O-chloroacetyl-β-
syluronate)-(1Ǟ3)-6-O-benzoyl-4-O-benzyl-2-deoxy-2-trichloro-
acetamido-1-O-trichloroacetimidoyl-α,β- -galactopyranose (15):
D-glucopyrano-
(s, 3 H, OCH3). MS (IS): m/z ϭ 1011 [Mϩ ϩ NH4], 960 [Mϩ
Ϫ
OCH3] for 35Cl. C46H45Cl4NO15 (993.66): calcd. C 55.60, H 4.56,
N 1.41; found C 55.50, H 4.60, N 1.52.
D
Glycoside 14 (4.6 g, 4.2 mmol) was submitted to the same proced-
ure as described for the preparation of imidate 7. Flash chromato-
graphy (petroleum ether/EtOAc, 3:1, containing 0.1% of Et3N) af-
forded an α,β-mixture of 15 (3.02 g, 64% from 14) as a white foam.
MS (IS): m/z ϭ 1140 [Mϩ ϩ NH4], 962 [Mϩ Ϫ OC(NH)CCl3] for
35Cl. C47H43Cl7N2O15 (1124.02): calcd. C 50.22, H 3.85, N 2.49;
found C 49.96, H 3.88, N 2.54.
Methyl (Methyl 2-O-benzoyl-3-O-benzyl-β-
nate)-(1Ǟ3)-6-O-benzoyl-4-O-benzyl-2-deoxy-2-trichloroacetamido-
β- -galactopyranoside (17): A mixture of ester 16 (2.3 g, 2.3 mmol)
D-glucopyranosyluro-
D
and thiourea (0.7 g, 9.2 mmol) in pyridine (11 mL) and abs. EtOH
(11 mL) was stirred for 40 min at 80 °C, and was then cooled, di-
luted with CH2Cl2 (100 mL), washed with water, brine, and water,
dried (MgSO4), and concentrated. Flash chromatography (petro-
leum ether/EtOAc, 3:2) and crystallization from EtOAc/petroleum
α-Anomer: Crystallized from diethyl ether/petroleum ether (2.3 g,
50% from 14). M.p. 110Ϫ111 °C. [α]2D2 ϭ ϩ38 (c ϭ 1, chloroform).
ether gave alcohol 17 (1.9 g, 91%). M.p. 176Ϫ178 °C. [α]2D2 ϭ Ϫ5
1H NMR (250 MHz, CDCl3): δ ϭ 8.70 (s, 1 H, CϭNH), 8.10Ϫ7.10 (c ϭ 1, chloroform). H NMR (250 MHz, CDCl3): δ ϭ 8.10Ϫ7.10
1
(m, 20 H, 4 Ph), 6.78 (d, J ϭ 8.3 Hz, 1 H, NH), 6.50 (d, J1,2
3.7 Hz, 1 H, GalN 1-H), 5.47 (dd, J1,2 ϭ 7.6, J2,3 ϭ 8.5 Hz, 1 H, 7.9, J2,3 ϭ 9.3 Hz, 1 H, GlcA 2-H), 4.85 (d, J1,2 ϭ 8.2 Hz, 1 H,
GlcA 2-H), 5.35 (dd, J3,4 ϭ 8.9, J4,5 ϭ 9.8 Hz, 1 H, GlcA 4-H), GalN 1-H), 4.84, 4.76 (2 ABq, 4 H, 2 CH2Ph), 4.76 (dd, J2,3
ϭ
(m, 20 H, 4 Ph), 6.77 (d, J ϭ 6.1 Hz, 1 H, NH), 5.34 (dd, J1,2 ϭ
ϭ
5.07 (d, 1 H, GlcA 1-H), 4.82 (m, J2,3 ϭ 10.7 Hz, 1 H, GalN 2-H), 11.1, J3,4 ϭ 2.6 Hz, 1 H, GalN 3-H), 4.74 (d, 1 H, GlcA 1-H), 4.48
4.70, 4.60 (2 ABq, 4 H, 2 CH2Ph), 4.42Ϫ4.34 (m, 5 H, GalN 3-H, (dd, J5,6a ϭ 6.4, J6a,6b ϭ 11.1 Hz, 1 H, GalN 6a-H), 4.30 (dd,
4-H, 5-H, 6a-H, 6b-H), 4.13 (d, 1 H, GlcA 5-H), 3.93 (dd, 1 H,
J5,6b ϭ 6.5 Hz, 1 H, GalN 6b-H), 4.14 (dd, J4,5 ϭ 0.8 Hz, GalN 4-
GlcA 3-H), 3.85 (ABq, 2 H, COCH2Cl), 3.68 (s, 3 H, COOCH3). H), 4.05 (m, J4,OH ϭ 2.4 Hz, 1 H, GlcA 4-H), 3.94 (d, 1 H, GlcA
13C NMR (67.8 MHz, CDCl3): δ ϭ 167.03, 166.12, 166.09, 165.13, 5-H), 3.85 (m, 1 H, GalN 5-H), 3.68 (dd, 1 H, GlcA 3-H), 3.66 (s,
161.73, 160.38 (CϭO, CϭN), 138.0Ϫ127.69 (ArC), 99.80 (GlcA C- 3 H, COOCH3), 3.53 (m, 1 H, GalN 2-H), 3.44 (s, 3 H, OCH3),
1), 95.07 (GalN C-1), 92.38, 90.94 (CCl3), 79.13, 75.29, 75.17, 3.08 (d, 1 H, GlcA 4-OH). 13C NMR (67.8 MHz, CDCl3): δ ϭ
74.80, 74.18, 72.54, 72.49, 72.41 (GlcA C-2, C-3, C-4, C-5; GalN
169.59, 166.23, 165.10, 162.49 (CϭO), 138.23Ϫ127.68 (ArC),
Eur. J. Org. Chem. 2002, 815Ϫ825
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