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S. C. Clough et al. / Tetrahedron 60 (2004) 10165–10169
(500 MHz, CDCl3) d 1.34 (t, JZ7.1 Hz, 3), 4.26 (q, JZ
7.2 Hz, 2), 6.03 (s, 2), 6.07 (dd, JZ0.8, 15.5 Hz, 1), 6.75
(dd, JZ0.8, 10.9 Hz, 1), 6.83 (d, JZ8.3 Hz, 1), 7.16
(d, JZ1.9 Hz, 1), 7.25 (dd, JZ1.9, 8.3 Hz, 1), and 7.82 ppm
(dd, JZ15.5, 10.9 Hz, 1); 13C NMR (125.8 MHz, CDCl3) d
14.3, 60.5, 101.7, 107.0, 108.2, 121.6, 122.1, 123.4, 131.2,
139.7, 1390.0, 148.1, 149.2, and 166.7 ppm; MS m/z 282
(6), 280(18), 245 (100), 235 (15), 217 (59), 207 (17), 172
(20), 149 (74), 131 (6), 117 (17), and 85 (14); HRMS
(EI, MC) calcd for C14H13O4Cl 280.0502, found 280.0494.
6.90 (d, JZ10.9 Hz, 1), 7.24 (d, JZ8.0 Hz, 2), 7.62 (d, JZ
8.0 Hz, 2) and 7.96 ppm (dd, JZ15.4, 10.9 Hz, 1); 13C
NMR (125.8 MHz, acetone-d6) d 123.9, 125.0, 127.3, 128.4,
133.0, 135.0, 137.3, 138.5, and 166.0 ppm; MS m/z 242
(13), 207 (100), 196 (6), 189 (7), 162 (20), 139 (18), and 115
(28); HRMS (EI, MC) calcd for C11H8O2Cl2 241.9901,
found 241.9896.
4.1.11. (2E,4Z)-5-Chloro-5-(p-fluorophenyl)-2,4-penta-
dienoic acid (3e). This compound was prepared from 2e
in 76% yield using the procedure described above for the
synthesis of 3a: mp 223–2258; IR (HATR) 3370–2180
4.1.7. (2E,4Z)-5-Chloro-5-phenyl-2,4-pentadienoic acid
(3a). A solution of ethyl (2E,4Z)-5-chloro-5-phenyl-2,4-
pentadienoate 2a (0.5 g, 2.12 mmol) in a 1:1 mixture of
H2O/EtOH (100 mL) was treated with NaOH (0.093 mL,
2.23 mmol) and stirred at room temperature. After 48 h, the
reaction mixture was made slightly acidic with 5% HCl
(10 mL), extracted into ethyl acetate (2!75 mL), dried
(MgSO4), and concentrated in vacuo. The crude product
was recrystallized in chloroform (10 mL) and filtered to
give 0.25 g (57%) of 3a as a yellow powder: mp 161–
163 8C; IR (HATR) 3200–2500 (broad), 3390, 2350, 2334,
1678, and 1600 cmK1; 1H NMR (500 MHz, CDCl3) d 6.29
(d, JZ15.9 Hz, 1), 7.29 (d, JZ10.9 Hz, 1), 7.49 (m, 3), and
7.82 ppm (m, 3); 13C NMR (125.8 MHz, acetone-d6) d
123.2, 124.4, 126.2, 128.2, 129.5, 136.2, 138.6, 138.7, and
166.1 ppm; MS m/z 208 (39), 191 (30), 173 (100), 162 (31),
127 (80), 115 (57), 105 (60), 86 (21), and 77 (64); HRMS
(EI, MC) calcd for C11H9ClO2 208.0291,, found 208.0288.
1
(broad), 1674, 1600, and 1425 cmK1; H NMR (500 MHz,
CDCl3) d 1.59 (s, 1), 6.14 (d, JZ15.2 Hz, 1), 6.86 (d, JZ
10.8 Hz, 1), 7.13 (m, 2), 7.71 (m, 3), and 7.93 ppm (dd, JZ
10.8, 15.2 Hz, 1); 13C NMR (125.8 MHz, acetone-d6) d
115.4 (d, JZ23.9 Hz), 124.5, 130.7, 132.3 (d, JZ8.3 Hz),
134.1, 134.2, 165.6 (d, JZ165.6 Hz), and 165.7 ppm; MS
m/z 226 (18), 191(100), 173 (11), 145 (40), 135 (24), 123
(33), 95 (10), and 73 (23); HRMS (EI, MC) calcd for
C11H8O2ClF 266.0197, found 266.0194.
4.1.12. (E)-5-Phenyl-pent-2-en-4-ynoic acid (4a) from 2a.
A slurry of sodium hydride (0.63 g, 0.026 mol) in dry N,N-
dimethylformamide (30 mL) was added to ethyl (2E,4Z)-5-
chloro-5-phenyl-2,4-pentadienoate (1.0 g, 0.00425 mol).
The resulting slurry was stirred at room temperature for
72 h. Water (200 mL) was carefully added followed by
50 mL of 18% HCl. The aqueous layer was extracted three
times with 30 mL of ethyl acetate. The organic layers were
combined and washed twice with water (25 mL), and dried
(MgSO4). Removal of solvent using a rotary evaporator
afforded 0.64 g (87%) of a crude solid. Recrystallization
from hexane yielded an analytical sample of (E)-5-phenyl-
pent-2-en-4-ynoic acid: mp 129–1328; IR (HATR)
4.1.8. (2E,4Z)-5-Chloro-5-(p-methylphenyl)-2,4-penta-
dienoic acid (3b). This compound was prepared from 2b
in 60% yield using the procedure described above for the
synthesis of 3a: mp 177–180 8C; IR (HATR) 3479, 3390,
1
3025, 2904, 1619, and 1541 cmK1; H NMR (300 MHz,
CDCl3) d 2.414 (s, 3H), (6.110 (d, JZ15.6 Hz, 1), 6.896
(d, 1H, JZ10.7 Hz, 1), 7.236 (d, 2H), 7.622 (d, 2H), 7.958
(dd,, JZ15.6, 10.7 Hz, 1); 13C NMR (125.8 MHz, acetone-
d6) d 21.2, 123.6, 125.3, 127.5, 130.2, 134.9, 140.2, 140.3,
141.3, and 167.5 ppm; MS m/z 222(29), 187 (100), 141 (73),
131 (37), 119 (77), 115 (75), 91 (38) and 10 (50); HRMS
(EI, MC) calcd for C12H11ClO2 222.0448,, found 222.0446.
3700–2200 (broad), 2197, 1665, 1614, and 1414 cmK1
;
1H NMR (500 MHz, CDCl3) d 6.34 (d, JZ15.9 Hz, 1), 7.11
(d, JZ15.9 Hz, 1), 7.40 (m, 3), and 7.52 ppm (m, 2); 13C
NMR (125.8 MHz, acetone-d6) d86.7, 98.5, 123.0, 125.5,
129.6, 130.4, 131.5, 132.7, and 166.5 ppm; MS m/z 172
(100), 146 (20), 144 (13), 127 (30), 122 (24), 115 (64), 105
(68), 97 (17), and 77 (75); HRMS (EI, MC) calcd for
C11H8O2 172.0524, found 172.0522.
4.1.9. (2E,4Z)-5-Chloro-5-(p-methoxyphenyl)-2,4-penta-
dienoic acid (3c). This compound was prepared from 2c in
63% yield using the procedure described above for the
synthesis of 3a. The crude solid was recrystallized from
hexane: mp 163–165 8C; IR (HATR) 2951 (broad), 2838,
4.1.13. (E)-5-(p-Methylphenyl)-2-penten-4-ynoic acid
(4b) from 2b. This compound was prepared from 2b in
87% yield using the procedure described above for the
synthesis of 4a: mp 173–179 8C; IR (HATR) 3700–2200
1
2528, 1669, 1588 cmK1; H NMR (500 MHz, CDCl3) d
(broad), 2182, 1680, 1593, and 1424 cmK1 1H NMR
;
3.78 (s, 3H), 6.09 (d, JZ15.5 Hz, 1), 6.755 (d, JZ10.9 Hz,
1), 6.86 (d, 2H), 7.58 (d, 2H), 7.87 (dd, JZ15.3, 15.4 Hz,
1H); 13C NMR (125.8 MHz, acetone-d6) d 55.9, 115.0,
122.5, 124.7, 129.1, 129.8, 140.1, 140.4, 162.3, and
167.5 ppm; MS m/z 238 (16), 203 (100), 158 (27), 135
(67), 115 (30), 89 (14), 77 (11), and 63 (19); HRMS
(EI, MC) calcd for C12H11ClO3 238.0397,, found 238.0404.
(500 MHz, CDCl3) d 2.4 (s, 3), 3.72 (s, 1), 6.31 (d, JZ
15.9 Hz, 1), 7.09 (d, JZ15.9 Hz, 1), 7.19 (d, JZ7.5 Hz, 2),
and 7.41 ppm (d, JZ7.5 Hz, 2); 13C NMR (125.8 MHz,
acetone-d6) d 21.5, 86.5, 92.9, 119.9, 125.8, 130.3, 131.0,
132.7, 140.8, and 166.5 ppm; MS m/z 187 (15), 186 (100),
171 (80), 157 (9), 139 (25), 129 (34), 115 (61), 90 (8), 75
(5), and 70(18); HRMS (EI, MC) calcd for C12H10O2
186.0677, found 186.0681.
4.1.10. (2E,4Z)-5-Chloro-5-(p-chlorophenyl)-2,4-pentan-
dienoic acid (3d). This compound was prepared from 2d in
52% yield using the procedure described above for the
synthesis of 3a: mp 218–222 8C; IR (HATR) 3321–1947
4.1.14. (E)-5-(p-Methoxyphenyl)-2-penten-4-ynoic acid
(4c) from 2c. This compound was prepared from 2c in 98%
yield using the procedure described above for the synthesis
of 4a: mp 164–165 8C; IR (HATR) 3200–2300 (broad),
(broad), 1674, 1600, 1577, and 1491 cmK1 1H NMR
;
1
(500 MHz, CDCl3) d 1.28 (s, 1), 6.11 (d, JZ15.4 Hz, 1),
2187, 1675, 1588, and 1414 cmK1; H NMR (500 MHz,