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Y. Geng et al. / Bioorg. Med. Chem. 21 (2013) 4793–4802
4.4 Hz, 1H), 3.27 (dd, J = 10.4, 2.8 Hz, 1H), 1.79 (br s, 2H); 13C NMR
(100 MHz, CDCl3) d 138.10, 137.92, 137.91, 137.48, 131.92, 128.59,
128.48, 128.40, 128.29, 128.14, 127.98, 127.84, 127.77, 127.62,
127.58, 118.92, 110.98, 79.53, 77.70, 76.48, 75.80, 73.98, 73.96,
73.57, 73.19, 73.06, 68.78, 54.92; HRMS (ESI) Calcd for C42H42N2O5-
Na [M+Na]+: 677.2991. Found: 677.2989. Compound 8b: Rf = 0.1
four portions at 0 °C. The mixture was warmed to rt and stirred
for 0.5 h, then poured into ice, extracted with ethyl acetate for
three times, the combined organic layer was washed with satd
NaHCO3 solution, dried, filtered and concentrated. The residue
was purified by column chromatography (petroleum ether/ethyl
acetate, 1.5:1) to afford 11b (91 mg, 83%) as a yellow foam:
(dichloromethane/methanol, 30:1); [
a
]
D
+13.5 (c 0.4, CHCl3); 1H
Rf = 0.3 (petroleum ether/ethyl acetate, 1:1); [
a
]
ꢀ33.1 (c 2.0,
D
NMR (400 MHz, CDCl3) d 7.48 (d, J = 8.4 Hz, 2H), 7.40–7.35 (m,
2H), 7.36–7.25 (m, 15H), 7.24–7.18 (m, 5H), 7.03–7.00 (m, 2H),
4.68 (d, J = 11.2 Hz, 1H), 4.62 (d, J = 11.6 Hz, 1H), 4.58 (d,
J = 12.4 Hz, 1H), 4.56 (d, J = 10.4 Hz, 1H), 4.54 (d, J = 12.0 Hz, 1H),
4.53 (d, J = 11.2 Hz, 1H), 4.40 (d, J = 8.0 Hz, 1H), 4.39 (d,
J = 12.0 Hz, 1H), 4.14–4.07 (m, 1H), 3.99 (dd, J = 9.2, 4.0 Hz, 1H),
3.92 (d, J = 11.2 Hz, 1H), 3.89 (t, J = 5.6 Hz, 1H), 3.75–3.68 (m,
2H), 3.63 (dd, J = 7.6, 5.6 Hz, 1H), 3.34 (dd, J = 6.0, 4.4 Hz, 1H),
1.95 (br s, 2H); 13C NMR (100 MHz, CDCl3) d 148.01, 138.10,
137.96, 137.87, 137.34, 131.95, 128.88, 128.43, 128.38, 128.24,
127.90, 127.79, 127.72, 127.64, 118.85, 110.98, 78.25, 77.15,
76.28, 76.20, 73.56, 73.55, 73.52, 73.38, 72.16, 69.29, 54.72; HRMS
(ESI) Calcd for C42H42N2O5Na [M+Na]+: 677.2991. Found: 677.3005.
CHCl3); 1H NMR (400 MHz, CDCl3) d 7.62–7.57 (m, 2H), 7.48 (d,
J = 8.4 Hz, 2H), 6.12 (d, J = 8.0 Hz, 1H), 5.26 (dd, J = 10.0, 2.4 Hz,
1H), 5.11 (t, J = 4.8 Hz, 1H), 4.86 (t, J = 4.8 Hz, 1H), 4.81 (br s, 1H),
4.28 (dd, J = 12.0, 7.2 Hz, 1H), 4.12–3.98 (m, 5H), 2.13 (s, 3H),
2.06 (s, 3H), 2.01 (s, 3H), 1.92 (s, 3H); 13C NMR (100 MHz, CDCl3)
d 170.20, 169.30, 169.20, 168.74, 154.18, 132.15, 129.73, 120.28,
118.14, 112.45, 77.20, 72.57, 68.02, 66.73, 66.36, 60.91, 55.30,
20.70, 20.70, 20.54, 20.43; HRMS (ESI) Calcd for C24H27N3O12Na
[M+Na]+: 572.1492. Found: 572.1498; IR (MeOH, cmꢀ1): 1443
(mNO); UV/Vis (MeOH): max 243 nm.
4.2.9. Compound 12b
Compound 12b was prepared from 8b following the same
procedure as 11b. The residue was purified by column chroma-
tography (petroleum ether/ethyl acetate, 1.2:1) to afford 12b
(75%) as a yellow oil: Rf = 0.25 (petroleum ether/ethyl acetate,
4.2.6. Compound 9b
To a solution of 7b (233 mg, 0.36 mmol) in CH2Cl2 (7 mL) was
added methyl chloroformate (55
l
L, 0.71 mmol) and triethylamine
1:1); [
a
]
D
+10.1 (c 1.7, CHCl3); 1H NMR (400 MHz, CDCl3) d
(0.2 mL, 1.43 mmol). The mixture was stirred at room temperature
for 2 h, then evaporated under vacuum and purified by column
chromatography (petroleum ether/ethyl acetate, 2.5:1) to afford
9b (224 mg, 88%) as a colorless glassy solid: Rf = 0.4 (petroleum
7.62 (d, J = 8.4 Hz, 2H), 7.55 (d, J = 8.4 Hz, 2H), 6.21 (d,
J = 7.2 Hz, 1H), 5.39 (dd, J = 11.2, 4.8 Hz, 1H), 5.22 (t, J = 6.8 Hz,
1H), 4.96–4.85 (m, 2H), 4.13–4.04 (m, 5H), 3.50 (br s, 1H), 2.07
(s, 3H), 2.05 (s, 3H), 2.04 (s, 3H), 1.58 (s, 3H); 13C NMR
(100 MHz, CDCl3) d170.20, 170.16, 169.33, 169.17, 153.92,
139.77, 131.99, 129.22, 118.21, 112.12, 77.20, 75.79, 74.20,
72.07, 71.24, 68.30, 62.14, 55.10, 20.55, 20.52, 20.49, 20.37;
HRMS (ESI) Calcd for C24H27N3O12Na [M+Na]+: 572.1492. Found:
572.1502.
ether/ethyl acetate, 1.5:1); [
a
]
D
+12.8 (c 0.5, CHCl3); 1H NMR
(400 MHz, CDCl3) d 7.49 (d, J = 8.4 Hz, 2H), 7.36–7.24 (m, 18H),
7.22–7.18 (m, 4H), 6.19 (br s, 1H), 5.14 (t, J = 6.8 Hz, 1H), 4.69 (d,
J = 11.6 Hz, 1H), 5.66 (d, J = 12.0 Hz, 1H), 4.63 (d, J = 10.4 Hz, 1H),
4.54 (d, J = 11.2 Hz, 1H), 4.52 (d, J = 11.2 Hz, 1H), 4.50 (d,
J = 12.0 Hz, 1H), 4.40 (d, J = 12.0 Hz, 1H), 4.33 (d, J = 11.2 Hz, 1H),
4.09 (br s, 1H), 4.00–3.96 (m, 1H), 3.87 (t, J = 5.6 Hz, 1H), 3.72
(dd, J = 8.0, 6.0 Hz, 1H), 3.63 (dd, J = 10.4, 4.4 Hz, 1H), 3.60 (s, 3H),
3.58–3.52 (m, 2H); 13C NMR (100 MHz, CDCl3) d 156.42, 145.77,
138.02, 137.91, 137.68, 137.00, 132.11, 128.63, 128.51, 128.40,
128.36, 128.23, 128.18, 127.98, 127.88, 127.81, 127.71, 127.68,
127.58, 118.77, 111.06, 77.20, 76.31, 73.98, 73.58, 73.40, 73.34
(2C), 72.91, 68.95, 56.11, 52.22; HRMS (ESI) Calcd for C44H45N2O7
[M+H]+: 713.3227. Found: 713.3218.
4.2.10. Compound 1b
To the solution of 11b (22 mg, 0.04 mmol) in anhydrous MeOH
(1 mL), was added MeONa (100 lL, 2 M solution in MeOH,
0.2 mmol). The mixture was stirred at room temperature for
5 min, and then concentrated in vacuo. The residue was purified
by column chromatography (ethyl acetate/methanol, 8:1) to afford
1b (11.5 mg, 95%) as an orange foam: Rf = 0.4 (ethyl acetate/meth-
anol, 5:1); [a]
+6.1 (c 1.0, MeOH); 1H NMR (400 MHz, CD3OD) d
D
7.64–7.62 (m, 2H), 7.31–7.26 (m, 2H), 5.24 (d, J = 6.4 Hz, 1H),
3.98 (dd, J = 10.0, 6.4 Hz, 1H), 3.71–3.66 (m, 2H), 3.62 (dd, J = 9.6,
8.4 Hz, 2H), 3.41 (t, J = 9.2 Hz, 1H); 13C NMR (100 MHz, MeOD) d
139.22, 133.54, 123.23, 113.84, 107.17, 76.02, 75.66, 74.14, 72.69,
72.08, 63.39, 62.63; HRMS (ESI) Calcd for C14H14N3O5 [MꢀH]ꢀ:
4.2.7. Compound 10b
To a solution of 9b (142 mg, 0.2 mmol) in ethyl acetate (10 mL)
was added palladium-on-carbon (10%, 108 mg, 0.1 mmol). After
hydrogenolysis for 5 h at room temperature, the mixture was fil-
tered and concentrated in vacuo. The residue was resolved in dry
pyridine (4 mL), Ac2O (0.4 mL, 4.0 mmol) was added then to the
solution. After stirring overnight at room temperature, the mixture
was coevaporated with toluene and purified by column chroma-
tography (petroleum ether/ethyl acetate, 1:1) to afford 10b
(92 mg, 90%) as a colorless glassy solid: Rf = 0.2 (petroleum ether/
304.0939. Found: 304.0951; IR (MeOH, cmꢀ1): 2071 (
UV/vis (MeOH): max 317 nm.
mC@N@N);
4.2.11. Compound 14
To a solution of 4b (65.5 mg, 0.1 mmol) in ethyl acetate (5 mL)
was added palladium-on-carbon (10%, 53 mg, 0.05 mmol). After
hydrogenolysis for 6 h at rt, the mixture was filtered and concen-
trated in vacuo. The residue was purified by column chromatogra-
phy (ethyl acetate/methanol, 4:1) to afford 14 (25.5 mg, 87%) as a
glassy solid: Rf = 0.25 (ethyl acetate/methanol, 5:1); 1H NMR
(400 MHz, CD3OD) 7.70 (d, J = 8.0 Hz, 2H), 7.63 (d, J = 8.0 Hz, 2H),
5.17 (d, J = 5.2 Hz, 1H), 4.16 (td, J = 6.4, 2.8 Hz, 1H), 4.03 (t,
J = 6.8 Hz, 1H), 3.91 (t, J = 4.8 Hz, 1H), 3.77 (dd, J = 12.0, 6.4 Hz,
1H), 3.64 (dd, J = 12.0, 2.4 Hz, 1H), 3.45 (dd, J = 4.8, 2.8 Hz, 2H),
3.41 (t, J = 6.8 Hz, 1H); 13C NMR (100 MHz, CD3OD) d 149.67,
132.95, 130.05, 129.93, 129.31, 119.88, 111.90, 79.63, 77.80,
74.29, 73.91, 72.08, 71.34, 62.33, 49.64, 49.43, 49.21, 49.00,
48.79, 48.57, 48.36; HRMS (ESI) Calcd for C14H16NO6 [M–H]–:
294.0978. Found: 294.0989.
ethyl acetate, 1:1.5); [a]
+4.0 (c 0.3, CHCl3); 1H NMR (400 MHz,
D
CDCl3) d 7.64 (d, J = 8.0 Hz, 2H), 7.46 (d, J = 8.4 Hz, 2H), 5.28 (d,
J = 9.2 Hz, 1H), 5.17–4.99 (m, 3H), 4.77 (t, J = 4.0 Hz, 1H), 4.42
(dd, J = 11.2, 8.8 Hz, 1H), 4.27 (dd, J = 8.8, 2.4 Hz, 1H), 4.10–4.00
(m, 1H), 3.87 (dd, J = 12.4, 4.0 Hz, 1H), 3.61 (s, 3H), 2.10 (s, 3H),
2.08 (s, 6H), 1.88 (s, 3H); 13C NMR (100 MHz, CDCl3) d 170.40,
169.66, 169.45, 168.60, 155.84, 144.37, 132.23, 128.40, 118.44,
111.70, 73.04, 69.99, 67.91, 66.53, 66.19, 60.13, 54.15, 52.58,
20.79, 20.77, 20.69, 20.52; MS (ESI) 543 [M+Na]+.
4.2.8. Compound 11b
Compound 10b (104 mg, 0.2 mmol) was dissolved in Ac2O/
HOAc (6 mL, v/v, 2:1), NaNO2 (276 mg, 4.0 mmol) was added in