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HETEROCYCLES, Vol. 80, No. 1, 2010
7.0 Hz, 1 H, CH), 6.14 (dd, 3J = 6.0 Hz, 3Jcis = 9.0 Hz, 1 H, CH), 6.49 (d, 3Jcis = 9.0 Hz, 1 H, CH), 7.07 –
7.10 (m, 2 H, CH), 7.21 – 7.26 (m, 1 H, CH), 7.55 (m, 1 H, CH), 11.95 (s, 1 H, OH). 13C-NMR (75 MHz,
CDCl3): = 46.5 (CH2), 48.8 (CH3), 49.3 (CH2), 50.2 (CH3), 53.2 (CH), 64.2 (CH2), 70.1 (CH2), 124.6,
125.7, 126.3, 126.4 (CH), 126.9 (C), 127.8, 128.3 (CH), 133.9, 154.4, 166.8, 199.8 (C). UV-Vis (,
~
log ): 231.40 (4.5). IR (KBr): = 2955 (w), 2931 (w), 2894 (w), 1744 (s), 1656 (w), 1489 (m), 1441 (s).
MS (EI, 70 eV): m/z (%) = 347 (M+, 1), 188 (100), 144 (51), 129 (22), 60 (16). Anal. Calcd for
C18H21NO6: C, 62.24; H, 6.09; N, 4.03. Found: C, 61.98; H, 6.14; N 4.19.
Ethyl 4-(1-N-benzyloxycarboyl-2-dihydroquinolyl)-3-oxobutanoate (4e). Starting with 1 (0.26 g,
2.0 mmol, 1.0 equiv.), 2a (1.098 g, 4.0 mmol, 2.0 equiv.), 3b (0.41 g, 2.4 mmol, 1.2 equiv.), and CH2Cl2
(20 mL), 4e was isolated by chromatography (silica gel, hexane/EtOAc = 7:1) as a yellow oil (0.109 g,
14%). 1H-NMR (300 MHz, CDCl3): = 1.20 - 1.31 (t, 3J = 7.0 Hz, 3 H, CH3), 2.68 - 2.75 (m, 2 H, CH2),
3.03 - 3.39 (m, 2 H, CH2, keto), 4.11 - 4.18 (q, 3J = 7.0 Hz, 2 H, CH2), 4.86 (s, 1 H, CH, enol), 5.17 - 5.32
(m, 2 H, CH2), 5.51 (dt, 3J = 6.0 Hz, 1 H, CH), 6.13 (dd, 3J = 6.0 Hz, 3Jcis = 9.0 Hz, 1 H, CH), 7.08 - 7.10
(m, 2 H, CH2), 7.20 - 7.23 (m, 1 H, CH), 7.31 - 7.38 (m, 5 H, CH), 7.56 (m, 1 H, CH), 12.04 (s, 1 H, OH).
13C-NMR (75 MHz, CDCl3): = 46.4 (CH2), 48.8 (CH3), 49.4 (CH2), 50.3 (CH), 61.3 (CH2), 67.9 (CH2),
124.6, 125.5, 126.4, 126.7 (CH), 127.7 (C), 127.9, 128.0, 128.0, 128.1, 128.3, 128.5 (CH), 133.8, 153.7,
~
166.7, 199.9 (C). IR (KBr): = 2983 (w), 1743 (s), 1652 (m), 1606 (w), 1491 (m), 1455 (m). UV-Vis (,
log ): 203.87 (4.6), 232.11 (4.5). MS (EI, 70 eV) m/z (%) = 393 (M+, 1), 264 (14), 220 (18), 129 (6), 91
(100). Anal. Calcd for C23H23NO5: C, 70.22; H, 5.89; N 3.56. Found: C, 70.10; H, 6.16; N, 3.51.
Methyl 4-(1-N-benzyloxycarboyl-2-dihydroquinolyl)-3-oxobutanoate (4f). Starting with 1 (0.26 g,
2.0 mmol, 1.0 equiv.), 2b (1.04 g, 4.0 mmol, 2.0 equiv.), 3b (0.82 g, 50% solution in toluene, 2.4 mmol,
1.2 equiv.), and 20 mL of CH2Cl2, 4f was isolated by chromatography (silica gel, hexane/EtOAc = 7:1) as
1
a yellow oil (0.18 g, 24%). H-NMR (300 MHz, CDCl3): = 2.68 - 2.74 (m, 2 H, CH2), 3.33 - 3.41 (m,
2 H, CH2, keto), 3.69, 3.72 (2 x s, 3 H, CH3, keto, enol), 4.88 (s, 1 H, CH, enol), 5.17 - 5.32 (m, 2 H,
3
3
3
3
CH2), 5.54 (dt, J = 6.0 Hz, 1 H, CH), 6.13 (dd, J = 6.0 Hz, Jcis = 9.0 Hz, 1 H, CH), 6.49 (d, Jcis
=
9.0 Hz, 1 H, CH) 7.08 - 7.10 (m, 2 H, CH), 7.19 - 7.24 (m, 1 H, CH), 7.32 - 7.37 (m, 5 H, CH), 7.55 (m,
1 H, CH), 11.97 (s, 1 H, OH). 13C-NMR (75 MHz, CDCl3): = 46.5 (CH2), 48.9 (CH3), 49.2 (CH2), 52.4
(CH), 68.0 (CH2), 124.7, 125.6, 125.8, 126.4 (CH), 126.8 (C), 127.8, 127.9, 128.1, 128.1, 128.2, 128.6
~
(CH), 133.9, 153.9, 167.2, 199.8 (C). IR (KBr): = 1747 (m), 1711 (s), 1657 (w), 1634 (w), 1491 (m),
1452 (m), 1441 (m). UV-Vis (, log ): 206.69 (4.2), 235.66 (4.5). MS (EI, 70 eV): m/z (%) = 379 (M+, 3),
264 (59), 220 (67), 142 (36), 91 (100). Anal. Calcd for C22H21NO5: C, 69.65; H, 5.58; N, 3.69. Found: C,