E. Caballero et al. / Tetrahedron 61 (2005) 6871–6878
6877
Characteristic signals for 14. 1H NMR 8.53 (d ppm) (1H, s,
H-2 Ind), 4.11 (1H, dd, JZ10.8, 2.0 Hz, H-3a).
saturated NaHCO3 dried and evaporated. The reaction
product was chromatographed on silica (hexane/EtOAc 7:3)
to give 18 (38 mg, 50%) and 19 (22 mg, 36%).
4.3.3. (6)(1R,4R,4aS,9aS)-2-[4-(1-Benzenesulfonyl-1H-
indol-3-yl-9,10-dioxo-2-triisopropylsiloxy-1,4,4a,9,9a,
10-hexahydro-1-anthryl]isoindole-1,3-dione (15). After
13 h reflux, 15 was isolated in 90% as a white solid. Mp
225 8C (hexane/AcOEt). 1H NMR (d ppm) 8.11 (1H, s, H-2
Ind), 8.3–7.2 (17H, Ar), 5.25 (1H, dd, JZ5.2, 1.6 Hz, H-6),
4.89 (1H, dd, JZ11.2, 1.6 Hz, H-4), 4.80 (1H, d, JZ5.2 Hz,
H-7), 3.89 (1H, dd, JZ11.2, 4.8 Hz, H-3a), 3.40 (1H, d, JZ
4.8 Hz, H-7a), 1.0–0.9 (TIPS). 13C NMR (d ppm) 195.1 (C),
194.7 (C), 167.8 (C), 167.6 (C), 145.7 (C), 137.9 (C), 135.8
(C), 134.8 (CH), 134.6 (2-CH), 134.3 (CH), 134.1 (CH),
134.1 (C), 133.6 (CH), 133.1 (C), 131.9 (2-C), 129.3 (C),
129.0 (2-CH), 127.4 (CH), 127.2 (2-CH), 127.0 (CH), 126.7
(CH), 124.8 (CH), 124.1 (C), 123.3 (2-CH), 118.5 (CH),
114.2 (CH), 103.5 (CH), 50.7 (CH), 48.3 (CH), 47.3 (CH),
28.7 (CH), 17.7 (6-CH3), 12.4 (3-CH). HRMS m/z calcd for
C45H44N2O7SSi 784.2716, found 784.2726.
4.4.1. (6)(3aS,4R,7aS)-4-(1-Benzenesulfonyl-1H-indol-3-
yl)-2-methyl-7-phthalimido-6-triisopropylsiloxy-3a,
4,5,7a-tetrahydroisoindole-1,3-dione (18). White solid.
1
Mp 252 8C (ether/MeOH). H NMR (d ppm) 8.04 (1H, d,
JZ8.2 Hz, H-7 Ind), 7.93 (1H, s, H-2 Ind), 7.56 (1H, d, JZ
7.2 Hz, H-4 Ind), 7.35 (1H, t, JZ8.2 Hz, H-6 Ind), 7.3–8.2
(10H, m, Ar), 4.20 (1H, m, H-7), 4.04 (1H, dd, JZ8.0,
2.4 Hz, H-3a), 3.42 (1H, t, JZ8.0 Hz, H-7a), 3.02 (3H, s,
N-Me), 2.86 (1H, ddd, JZ16.8, 2.8, 1.2 Hz, H-6), 2.38 (1H,
d, JZ16.8 Hz, H-6), 1.0–0.8 (TIPS). 13C NMR (d ppm)
177.2 (C), 175.2 (C), 167.8 (C), 166.0 (C), 149.7 (C), 133.9
(CH), 133.8 (CH), 138.2 (C), 134.7 (C), 133.5 (CH), 132.5
(C), 132.2 (C), 129.5 (C), 129.1 (2-CH), 127.4 (2-CH),
124.9 (CH), 123.6 (CH), 123.5 (CH), 123.3 (CH), 123.1
(CH), 122.3 (C), 118.6 (CH), 113.7 (CH), 102.1 (C), 44.2
(CH), 41.3 (CH), 32.3 (CH2), 28.1 (CH), 25.1 (CH3), 16.9
(6-CH3), 12.8 (3-CH). Anal. Calcd for C40H43N3O7SSi: C,
65.10; H, 5.87; N, 5.69; S, 4.35. Found: C, 65.34; H, 6.00;
N, 5.91; S, 4.19.
4.3.4. (6)(3aS,4R,7R,7aS)-2-Methyl-7-(2-nitrophenyl)-4-
phthalimido-5-triisopropylsiloxy-3a,4,7,7a-tetrahydro
isoindole-1,3-dione (16). After 7 h reflux, 16 was isolated in
87% yield as a yellow solid. 1H NMR (d ppm) 7.90 (1H, dd,
JZ7.8, 1.5 Hz, H-3Ar), 7.79 (1H, dd, JZ7.8, 1.5 Hz,
H-6Ar), 7.71 (1H, td, JZ7.8, 1.5 Hz, 1H, H-5Ar), 7.45 (1H,
dt, JZ7.8, 1.5 Hz, H-4Ar), 7.7–8.0 (4H, m, Pht), 5.10 (1H,
dt, JZ8.0, 2.4 Hz, H-4), 4.91 (1H, t, JZ2.4 Hz, H-6), 4.50
(1H, dt, JZ8.0, 2.4 Hz, H-7), 3.82 (1H, t, JZ8.0 Hz, H-3a),
3.27 (1H, t, JZ8.0 Hz, H-7a), 2.99 (3H, s, N-Me), 1.1–0.8
(TIPS). 13C NMR (d ppm) 176.3 (2-C), 167.7 (2-C), 149.4
(C), 147.4 (C), 138.1 (C), 134.1 (2-CH), 133.5 (CH), 131.9
(2-C), 130.6 (CH), 128.0 (CH), 124.6 (CH), 123.4 (2-CH),
103.8 (CH), 46.1 (CH), 45.4 (CH), 42.8 (CH), 35.1 (CH),
24.8 (CH3), 17.7 (6-CH3), 12.4 (3-CH). HRMS m/z calcd for
C32H37N3O7Si 603.2401 found, 603.2479.
4.4.2. (6)(3aS,4R,7R,7aS)-7-(1-Benzenesulfonyl-1H-
iso-
indol-3-yl)-2-methyl-4-phthalimidotetrahydro
indole-1,3,5-trione (19). White solid. Mp 196 8C (ether/
MeOH). 1H NMR (d ppm) 7.98 (1H, d, JZ8.2 Hz, H-7 Ind),
7.70 (1H, s, H-2 Ind), 7.55 (1H, d, JZ7.3 Hz, H-4 Ind), 7.35
(1H, t, JZ7.2 Hz, H-6 Ind), 7.2–8.0 (10H, m, Ar), 5.09 (1H,
d, JZ12.1 Hz, H-4), 4.17 (1H, dd, JZ12.0, 9.4 Hz, H-3a),
3.93 (1H, td, JZ11.0, 4.8 Hz, H-7), 3.73 (1H, dd, JZ11.0,
9.4 Hz, H-7a), 2.98 (3H, s, N-Me), 2.93 (2H, m, H-6). 13C
NMR (d ppm) 199.1 (C), 175.3 (2-C), 167.4 (2-C), 138.0
(C), 135.3 (C), 134.3 (2-CH), 133.8 (CH), 131.7 (2-C),
129.2 (2-CH), 126.9 (2-CH), 125.2 (CH), 124.1 (CH), 123.8
(2-CH), 123.4 (CH), 121.3 (C), 119.0 (CH), 117.4 (C), 114.1
(CH),54.1(CH),43.9(CH),43.7(CH2),39.0(CH), 30.4(CH),
25.1 (CH3). Anal. Calcd for C31H23N3O7S: C, 64.02; H, 3.99;
N, 7.22; S, 5.51. Found: C, 64.34; H, 4.020; N, 7.51; S, 5.19.
4.3.5. (6)(1R,4R,4aS,9aS)-2-[4-(2-Nitrophenyl-9,10-
dioxo-2-triisopropylsiloxy-1,4,4a,9,9a,10-hexahydro-1-
anthryl]isoindole-1,3-dione (17). After 7 h reflux, 17 was
1
isolated in 84% yield as a brown solid. H NMR (d ppm)
4.4.3. (6)(3aS,4R,7R,7aS)-7-(1-Benzenesulfonyl-1H-
indol-3-yl)-5-hydrazono-2-methyl-4-phthalimido hexa-
hydroisoindole-1,3-dione (20). One millimole of 19 in
EtOH was treated with 3 mmol of hydrazine hydrate for
24 h at reflux. By crystallization, 20 was isolated in 90%
yield as a yellow solid. Mp 239 8C (ether/MeOH). 1H NMR
(d ppm) 7.96 (1H, d, JZ8.2 Hz, H-7 Ind), 7.72 (1H, s, H-2
Ind), 7.52 (1H, d, JZ7.3 Hz, H-4 Ind), 7.33 (1H, t, JZ
7.2 Hz, H-6 Ind), 7.2–8.0 (10H, m, Ar), 5.26 (1H, d, JZ
12.0 Hz, H-4), 4.38 (1H, dd, JZ12.0, 9.2 Hz, H-3a), 3.68
(1H, td, JZ9.0, 4.0 Hz, H-7), 3.59 (1H, t, JZ9.2 Hz, H-7a),
2.94 (3H, s, N-Me), 2.93 (2H, m, H-6). 13C NMR (d ppm)
175.8 (2-C), 167.9 (2-C), 141.1 (C), 138.1 (C), 134.0
(2-CH), 135.3 (C), 132.0 (2-C), 133.7 (CH), 129.2 (2-CH),
126.9 (2-CH), 126.0 (CH), 125.8 (C), 124.1 (CH), 123.8
(2-CH), 123.5 (CH), 121.9 (C), 119.1 (CH), 114.1 (CH),
49.3 (CH), 43.5 (CH), 39.2 (CH), 31.7 (CH2), 30.4 (CH),
24.9 (CH3). Anal. Calcd for C31H24N4O6: C, 64.10; H, 4.17;
N, 9.85; S, 5.52. Found: C, 63.90; H, 4.46; N, 9.88; S, 5.49.
8.41 (1H, dd, JZ8.1, 1.2 Hz, H-6Ar), 8.17 (1H, dd, JZ7.5,
1.2 Hz, H-9), 7.96 (1H, dd, JZ7.5, 1.2 Hz, H-2), 7.92 (1H,
dd, JZ8.1, 1.2 Hz, H-3Ar), 7.76 (1H, td, JZ8.0, 1.2 Hz,
1H, H-5Ar), 7.7–7.9 (6H, m, H-1, H-10, Pht), 7.46 (1H, dt,
JZ8.1, 1.2 Hz, H-4Ar), 5.08 (1H, d, JZ5.2 Hz, H-7), 5.05
(1H, dd, JZ5.2, 1.2 Hz, H-6), 4.95 (1H, dd, JZ10.8,
1.2 Hz, H-4), 4.00 (1H, dd, JZ10.8, 4.8 Hz, H-3a), 3.82
(1H, d, JZ4.8 Hz, H-7a), 1.1–0.8 (TIPS). 13C NMR (d ppm)
195.2 (C), 193.6 (C), 167.6 (2C), 148.9 (C), 146.9 (C), 137.3
(C), 134.8 (CH), 134.6 (CH), 133.5 (C), 133.4 (CH), 132.8
(CH), 131.8 (2-CH), 131.7 (2-C), 130.3 (C), 128.0 (CH),
127.4 (CH), 127.3 (CH), 127.0 (CH), 123.3 (2-CH), 104.2
(CH), 51.9 (CH), 48.3 (CH), 47.5 (CH), 33.8 (CH), 17.3
(6-CH3), 12.7 (3-CH). HRMS m/z calcd for C37H38N2O7Si
650.2448, found 650.2526.
4.4. Hydrolysis of cycloadduct 2a (18 and 19)
Compound 2a (75 mg, 0.10 mmol) dissolved in 4 mL of
CH2Cl2 was treated with concentrated HCl (360 ml) and
then stirred for 24 h. The reaction mixture was washed with
4.4.4. 7-(1-Benzenesulfonyl-1H-indol-3-yl)-2-methyl-4-
phthalimido-5-triisopropylsiloxyisoindole-1,3-dione