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A. Wada et al. / Bioorg. Med. Chem. 12 (2004) 3931–3942
from the E-acetylenic compound (12, 200 mg,
0.93 mmol) and the triflate (16d, 284 mg, 0.93 mmol) in
44% yield (150 mg, two steps) as a pale yellow oil.
J ¼ 16 Hz), 6.65 (1H, d, J ¼ 16 Hz), 7.10 (1H, dd,
J ¼ 15, 11.5 Hz); 13C NMR(75 MHz) d: 14.08, 14.28,
19.15, 20.80, 21.05, 21.76, 28.94 (2C), 33.06, 34.18,
39.48, 59.54, 117.37, 128.06, 129.36, 129.47, 130.00,
130.12, 132.95, 137.92, 138.20, 159.10, 166.63; HRMS
(EI) m=z: Calcd for C23H34O2 (Mþ) 342.2557. Found:
342.2556.
UV–vis kmax nm: 357; IR mmax cmÀ1: 1698, 1604; 1H
NMR(300 MHz) d: 0.95 (2H, t, J ¼ 7 Hz), 1.03 (6H, s),
1.29 (3H, t, J ¼ 7 Hz), 1.40–1.52 (4H, m), 1.57–1.65 (4H,
m), 1.71 (3H, s), 2.00 (3H, s), 2.02 (2H, t, J ¼ 6:5 Hz),
2.83 (2H, q, J ¼ 7 Hz), 4.16 (2H, q, J ¼ 7 Hz), 5.73 (1H,
s), 6.13 (1H, d, J ¼ 16 Hz), 6.14 (1H, d, J ¼ 11 Hz), 6.19
(1H, d, J ¼ 15 Hz), 6.27 (1H, d, J ¼ 16 Hz), 7.00 (1H,
dd, J ¼ 15, 11 Hz); 13C NMR(75 MHz) d: 12.84, 13.92,
14.30, 19.17, 21.67, 23.02, 27.50, 28.90 (2C), 31.95,
33.04, 34.21, 39.54, 59.53, 117.79, 128.54, 129.60,
129.90, 130.50, 134.21, 137.24, 137.67, 139.32, 157.76,
166.72; HRMS (EI) m=z: Calcd for C25H38O2 (Mþ)
370.2870. Found: 370.2870.
4.3.8. Ethyl (2E,4E,6Z,8E)-7-methyl-3-propyl-9-(2,6,6-tri-
methyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraenoate (18c).
This was prepared from the stannylolefin 15 prepared
from the Z-acetylenic compound (13, 180 mg, 0.84 mmol)
and the triflate (16c, 240 mg, 0.84 mmol) in 48% yield
(143 mg, two steps) as a pale yellow oil.
UV–vis kmax nm: 353; IR mmax cmÀ1: 1699, 1586; 1H
NMR(300 MHz) d: 0.99 (2H, t, J ¼ 7:5 Hz), 1.05 (6H,
s), 1.27 (3H, t, J ¼ 7 Hz), 1.43–1.49 (2H, m), 1.52–1.64
(4H, m), 1.76 (3H, s), 1.99 (3H, s), 2.05 (2H, t,
J ¼ 6 Hz), 2.82 (2H, q, J ¼ 7:5 Hz), 4.15 (2H, q,
J ¼ 7 Hz), 5.73 (1H, s), 6.04 (1H, d, J ¼ 11:5 Hz), 6.12
(1H, d, J ¼ 15 Hz), 6.28 (1H, d, J ¼ 16 Hz), 6.66 (1H, d,
J ¼ 16 Hz), 7.09 (1H, dd, J ¼ 15, 11.5 Hz); 13C NMR
(75 MHz) d: 14.29 (2C), 19.15, 20.76, 21.73, 23.07, 28.94
(2C), 29.69, 33.13, 34.16, 39.58, 59.50, 117.83, 128.03,
129.32, 129.44, 129.88, 130.37, 133.36, 137.80, 138.20,
157.52, 166.70; HRMS (EI) m=z: Calcd for C24H36O2
(Mþ) 356.2713. Found: 356.2707.
4.3.5. Ethyl (2E,4E,6E,8E)-7-methyl-3-(2-phenyl)ethyl-9-
(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraeno-
ate (17e). This was prepared from the stannylolefin 14
prepared from the E-acetylenic compound (12, 200 mg,
0.93 mmol) and the triflate (16e, 329 mg, 0.93 mmol) in
65% yield (253 mg, two steps) as a pale yellow oil.
UV–vis kmax nm: 357; IR mmax cmÀ1: 1698, 1604; 1H
NMR(300 MHz) d: 1.03 (6H, s), 1.29 (3H, t, J ¼ 7 Hz),
1.45–1.49 (2H, m), 1.58–1.66 (2H, m), 1.72 (3H, s), 1.99
(3H, s), 2.05 (2H, t, J ¼ 6:5 Hz), 2.80 (2H, t,
J ¼ 8:5 Hz), 3.14 (2H, t, J ¼ 8:5 Hz), 4.18 (2H, q,
J ¼ 7 Hz), 5.78 (1H, s), 6.14 (1H, d, J ¼ 16:5 Hz), 6.15
(1H, d, J ¼ 11 Hz), 6.22 (1H, d, J ¼ 15 Hz), 6.29 (1H, d,
J ¼ 16:5 Hz), 7.01 (1H, dd, J ¼ 15, 11 Hz), 7.20–7.34
(5H, m); 13C NMR(75 MHz) d: 12.88, 14.33, 19.17,
21.69, 28.91 (2C), 30.11, 33.06, 34.21, 35.95, 39.57,
59.65, 118.24, 125.92, 128.33 (2C), 128.44 (2C), 128.74,
129.49, 130.00, 130.78, 133.74, 137.18, 137.67, 139.61,
142.00, 156.46, 166.58; HRMS (EI) m=z: Calcd for
C29H38O2 (Mþ) 418.2870. Found: 418.2868.
4.3.9. Ethyl (2E,4E,6Z,8E)-3-butyl-7-methyl-9-(2,6,6-tri-
methyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraenoate (18d).
This was prepared from the stannylolefin 15 prepared
from the Z-acetylenic compound (13, 200 mg,
0.93 mmol) and the triflate (16d, 250 mg, 0.93 mmol) in
58% yield (253 mg, two steps) as a pale yellow oil.
UV–vis kmax nm: 354; IR mmax cmÀ1: 1698, 1586; 1H
NMR(300 MHz) d: 0.94 (2H, t, J ¼ 7:5 Hz), 1.06 (6H,
s), 1.28 (3H, t, J ¼ 7 Hz), 1.41–1.51 (4H, m), 1.58–1.68
(4H, m), 1.75 (3H, s), 2.00 (3H, s), 2.05 (2H, t,
J ¼ 6:5 Hz), 2.83 (2H, q, J ¼ 7:5 Hz), 4.18 (2H, q,
J ¼ 7 Hz), 5.73 (1H, s), 6.05 (1H, d, J ¼ 11:5 Hz), 6.12
(1H, d, J ¼ 15 Hz), 6.29 (1H, d, J ¼ 16:5 Hz), 6.67 (1H,
d, J ¼ 16:5 Hz), 7.10 (1H, dd, J ¼ 15, 11.5); 13C NMR
(75 MHz) d: 13.88, 14.29, 19.14, 20.75, 21.70, 23.08,
27.56, 28.94 (2C), 31.95, 33.15, 34.16, 39.61, 59.51,
117.68, 128.00, 129.26, 129.47, 129.93, 130.43, 133.31,
137.79, 138.24, 157.79, 166.72; HRMS (EI) m=z: Calcd
for C25H38O2 (Mþ) 370.2870. Found: 370.2878.
4.3.6. Ethyl (9Z)-retinoate (18a). This was prepared from
the stannylolefin 15 prepared from the Z-acetylenic
compound (13, 189 mg, 0.93 mmol) and the triflate (16a,
231 mg, 0.88 mmol) in 39% yield (113 mg, two steps) as a
pale yellow oil. The spectral data of this compound was
identical with those of literature.5c
4.3.7. Ethyl (2E,4E,6Z,8E)-3-ethyl-7-methyl-9-(2,6,6-tri-
methyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraenoate (18b).
This was prepared from the stannylolefin 15 prepared
from the Z-acetylenic compound (13, 169 mg,
0.79 mmol) and the triflate (16b, 218 mg, 0.79 mmol) in
45% yield (121 mg, two steps) as a pale yellow oil.
4.3.10. Ethyl (2E,4E,6Z,8E)-7-methyl-3-(2-phenyl)ethyl-
9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetra-
enoate (18e). This was prepared from the stannylolefin 15
prepared from the Z-acetylenic compound (13, 200 mg,
0.93 mmol) and the triflate (16e, 329 mg, 0.93 mmol) in
57% yield (221 mg, two steps) as a pale yellow oil.
1
IR mmax cmÀ1: 1700, 1585; H NMR(300 MHz) d: 1.04
(6H, s), 1.14 (3H, t, J ¼ 7 Hz), 1.29 (3H, t, J ¼ 7 Hz),
1.44–1.49 (2H, m), 1.59–1.66 (2H, m), 1.75 (3H, s), 2.00
(3H, s), 2.04 (2H, t, J ¼ 6:5 Hz), 2.86 (2H, q, J ¼ 7 Hz),
4.16 (2H, q, J ¼ 7 Hz), 5.71 (1H, s), 6.05 (1H, d,
J ¼ 11:5 Hz), 6.12 (1H, d, J ¼ 15 Hz), 6.27 (1H, d,
UV–vis kmax nm: 350, 205; IR mmax cmÀ1: 1698, 1586; 1H
NMR(300 MHz) d: 1.06 (6H, s), 1.30 (3H, t, J ¼ 7 Hz),
1.49–1.55 (2H, m), 1.60–1.68 (2H, m), 1.76 (3H, s), 2.01