The Journal of Organic Chemistry
Note
7.26−7.27 (m, 3H), 7.37−7.39 (m, 2H); 13C NMR (125 MHz,
CDCl3) δ 15.4, 19.0, 27.7, 33.7, 70.7, 81.1, 88.0, 123.5, 127.7, 128.1,
131.5, 171.9. IR (KBr) νmax 3055, 2963, 2214, 1738, 1599, 1491 cm−1;
MS m/z = 231 [M + H+]. Anal. Calcd for C15H18O2: C, 78.23; H, 7.88.
Found: C, 78.06; H, 8.02.
2204, 1739, 1596, 1490 cm−1; MS m/z = 195 [M + H+]. Anal. Calcd
for C10H10O2S: C, 61.83; H, 5.19. Found: C, 61.66; H, 5.44.
Methyl 2-Methyl-5-phenylpent-4-ynoate (3ae). Pale yellow
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oil; H NMR (500 MHz, CDCl3) δ 1.34 (d, J = 6.9 Hz, 3H), 2.60
(m, 1H), 2.73−2.80 (m, 2H), 3.72 (s, 3H), 7.27−7.29 (m, 3H), 7.38−
7.41 (m, 2H); 13C NMR (125 MHz, CDCl3) δ 16.5, 23.6, 38.9, 51.9,
82.1, 87.0, 123.5, 127.5, 128.2, 131.5, 175.5; IR (KBr) νmax 3034, 2953,
2223, 1742, 1598, 1587, 1491 cm−1; MS m/z = 203 [M + H+]. Anal.
Calcd for C10H10O2S: C, 77.20; H, 6.98. Found: C, 77.06; H, 7.21.
Methyl 5-(4-Methoxyphenyl)-4-pentynoate (3cb). Yellow oil;
1H NMR (400 MHz, CDCl3) δ 2.62 (t, J = 7.3 Hz, 2H), 2.71 (t, J =
6.7 Hz, 2H), 3.71 (s, 3H), 3.78 (s, 3H), 6.80 (d, J = 8.9 Hz, 2H), 7.31
(d, J = 8.9 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 15.4, 33.6, 51.7,
55.2, 80.9, 86.3, 113.8, 115.7, 132.9, 159.2, 172.4; IR (KBr) νmax 3002,
2954, 2225, 1739, 1607, 1511 cm−1; MS m/z = 219 [M + H+]. Anal.
Calcd for C13H14O3: C, 71.54; H, 6.47. Found: C, 71.32; H, 6.79.
n-Butyl 5-(4-Methoxyphenyl)-4-pentynoate (3cc). Yellow oil;
1H NMR (400 MHz, CDCl3) δ 0.92 (t, J = 7.4 Hz, 3H), 1.43−1.34
(m, 2H), 1.66−1.58 (m, 2H), 2.61 (t, J = 7.4 Hz, 2H), 2.71 (t, J = 6.6
Hz, 2H), 3.78 (s, 3H), 4.12 (t, J = 6.7 Hz, 2H), 6.80 (d, J = 8.9 Hz,
2H), 7.31 (d, J = 8.9 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 13.6,
15.4, 19.1, 30.7, 33.8, 55.2, 64.5, 80.9, 86.4, 113.8, 115.7, 132.9, 159.2,
172.1; IR (KBr) νmax 3041, 2958, 2220, 1736, 1607, 1510 cm−1;
MS m/z = 261 [M + H+]. Anal. Calcd for C16H20O3: C, 73.82; H, 7.74.
Found: C, 73.61; H, 7.88.
Isobutyl 5-(4-Methoxyphenyl)-4-pentynoate (3cd). Pale
yellow oil; 1H NMR (400 MHz, CDCl3) δ 0.93 (d, J = 6.7 Hz,
6H), 1.93 (m, 1H), 2.61 (t, J = 6.7 Hz, 2H), 2.70 (t, J = 7.2 Hz, 2H),
3.76 (s, 3H), 3.89 (d, J = 6.6 Hz, 2H), 6.78 (d, J = 8.9 Hz, 2H), 7.30
(d, J = 8.9 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 15.3, 18.9, 27.6,
33.7, 55.1, 70.6, 80.8, 86.3, 113.7, 115.6, 132.8, 159.1, 171.9; IR (KBr)
νmax 3041, 2961, 2046, 1733, 1607, 1509 cm−1; MS m/z = 261
[M + H+]. Anal. Calcd for C16H20O3: C, 73.82; H, 7.74. Found: C,
73.60; H, 7.88.
Methyl 5-(2-Methylphenyl)-4-pentynoate (3eb). Yellow oil;
1H NMR (400 MHz, CDCl3) δ 2.40 (s, 3H), 2.65 (t, J = 7.7 Hz, 2H),
2.78 (t, J = 7.1 Hz, 2H), 3.72 (s, 3H), 7.07−7.12 (m, 1H), 7.17 (dd,
J = 5.1, 1.1 Hz, 2H), 7.35 (d, J = 7.4 Hz, 1H). 13C NMR (100 MHz,
CDCl3) δ 15.5, 20.5, 33.7, 51.7, 80.1, 91.8, 123.2, 125.4, 127.7, 129.2,
131.8, 140.0, 172.3; IR (KBr) νmax 3062, 2952, 2233, 1741, 1601,
1486 cm−1; MS m/z = 203 [M + H+]. Anal. Calcd for C13H14O2: C,
77.20; H, 6.98. Found: C, 77.07; H, 7.12.
n-Butyl 5-(2-Methylphenyl)-4-pentynoate (3ec). Yellow oil;
1H NMR (400 MHz, CDCl3) δ 0.93 (t, J = 7.4 Hz, 3H), 1.38−1.40
(m, 2H), 1.61−1.63 (m, 2H), 2.40 (s, 3H), 2.64 (t, J = 7.2 Hz, 2H),
2.78 (t, J = 7.1 Hz, 2H), 4.13 (t, J = 6.7 Hz, 2H), 7.07−7.13 (m, 1H),
7.17 (dd, J = 5.1, 1.1 Hz, 2H), 7.35 (d, J = 7.4 Hz, 1H); 13C NMR
(100 MHz, CDCl3) δ 13.6, 15.6, 19.1, 20.6, 30.6, 33.9, 64.5, 80.1, 92.0,
123.3, 125.4, 127.7, 129.2, 131.8, 140.0, 172.0; IR (KBr) νmax 3062,
2960, 2236, 1737, 1601, 1487 cm−1; MS m/z = 245 [M + H+]. Anal.
Calcd for C16H20O2: C, 78.65; H, 8.25. Found: C, 78.32; H, 8.38.
Isobutyl 5-(2-Methylphenyl)-4-pentynoate (3ed). Yellow oil;
1H NMR (400 MHz, CDCl3) δ 0.95 (d, J = 6.7 Hz, 6H), 1.96
(m, 1H), 2.40 (s, 3H), 2.66 (t, J = 7.8 Hz, 2H), 2.79 (t, J = 7.2 Hz,
2H), 3.92 (d, J = 6.7 Hz, 2H), 7.07−7.13 (m, 1H), 7.17 (dd, J = 5.1,
1.2 Hz, 2H), 7.35 (d, J = 7.4 Hz, 1H); 13C NMR (100 MHz, CDCl3)
δ 15.6, 19.0, 20.6, 27.7, 33.9, 70.7, 80.0, 92.0, 123.3, 125.3, 127.7, 129.2,
131.8, 140.0, 171.9; IR (KBr) νmax 3023, 2963, 2231, 1738, 1601,
1486 cm−1; MS m/z = 245 [M + H+]. Anal. Calcd for C16H20O2: C,
78.65; H, 8.25. Found: C,78.46; H, 8.37.
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Ethyl 5-n-Butyl-4-pentynoate (3ga). Yellow oil; H NMR (500
MHz, CDCl3) δ 0.86 (t, J = 7.2 Hz, 4H), 1.23 (t, J = 7.2 Hz, 3H), 1.38
(m, 4H), 2.09 (t, J = 6.9 Hz, 2H), 2.45 (t, J = 4.2 Hz, 3H), 4.12 (q, J =
7.1 Hz, 2H). 13C NMR (125 MHz, CDCl3) δ 13.5, 14.1, 14.7, 18.3,
21.8,31.0, 34.1, 60.4, 78.0, 81.0, 172.1. IR (KBr) νmax 2953, 2164, 1740
1460, 1360 cm−1; MS m/z =183 [M + H+]. Anal. Calcd for C11H18O2:
C, 72.49; H, 9.95. Found: C, 72.26; H, 10.11.
5-Phenyl-pent-4-ynoic Acid 6-(5-phenyl-pent-4-ynoyloxy)-
hexyl Ester10 (3af). Yellow oil; 1H NMR (500 MHz, CDCl3)
δ 1.35−1.38 (m, 4H), 1.59−1.63 (m, 4H), 2.62 (t, J = 7.3 Hz, 4H), 2.73
(t, J = 7.5 Hz, 4H), 4.09 (t, J = 6.6 Hz, 4H), 7.26−7.28 (m,6H), 7.37−
7.39 (m, 4H); 13C NMR (125 MHz, CDCl3) δ 15.4, 25.6, 28.5, 33.0,
64.6, 81.2, 88.0, 123.5, 127.8, 128.2, 131.6, 172.0. IR (KBr) νmax 3056,
2938, 2240, 1732, 1598, 1572, 1491 cm−1; MS m/z = 431 [M + H+].
Anal. Calcd for C28H30O4: C, 78.11; H, 7.02. Found: C, 78.36; H, 6.88.
5-(2-Methylphenyl)-pent-4-ynoic Acid 6-(5-(2-Methylphen-
yl)-pent-4-ynoyloxy)-hexyl Ester10 (3ef). Yellow oil; 1H NMR
(400 MHz, CDCl3) δ 1.35−1.40 (m, 4H), 1.60−1.65 (m, 4H), 2.39 (s,
6H), 2.64 (t, J = 7.7 Hz, 4H), 2.77 (t, J = 7.0 Hz, 4H), 4.12 (t, J = 6.6
Hz, 4H), 7.06−7.12 (m, 2H), 7.17 (dd, J = 5.1, 1.1 Hz, 4H), 7.34 (d,
J = 7.4 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 15.6, 20.5, 25.6, 28.5,
33.9, 64.6, 80.1, 91.9, 123.2, 125.4, 127.7, 129.3, 131.8, 140.0, 171.9; IR
(KBr) νmax 3060, 2982, 2238, 1735, 1608, 1498 cm−1; MS m/z = 459
[M + H+]. Anal. Calcd for C30H34O4: C, 78.57; H, 7.43. Found: C,
78.40; H, 7.68.
5-Thiophen-3-yl-pent-4-ynoic Acid 6-(5-Thiophen-3-yl-pent-
4-ynoyloxy)-hexyl Ester10 (3ff). Yellow oil; H NMR (500 MHz,
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CDCl3) δ 1.35−1.38 (m, 4H), 1.61−1.63 (m, 4H), 2.60 (t, J = 7.2 Hz,
4H), 2.71 (t, J = 7.1 Hz, 4H), 4.10 (t, J = 6.6 Hz, 4H), 7.05 (dd, J =
4.9, 1.0 Hz, 2H), 7.22 (dd, J = 4.9, 3.0 Hz, 2H), 7.35 (d, J = 1.9 Hz,
2H); 13C NMR (125 MHz, CDCl3) δ 15.4, 25.6, 28.5, 33.7, 87.6, 64.6,
76.3, 122.6, 125.0, 128.0, 130.0, 171.9. IR (KBr) νmax 3106, 2934,
2208, 1731, 1521, 1465 cm−1; MS m/z = 443 [M + H+]. Anal. Calcd
for C24H26O4S2: C, 65.13; H, 5.92. Found: C, 64.96; H, 6.08.
Diethyl 5,5′-(1,4-Phenylene)dipent-4-ynoate11 (3ia). Brown
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solid; mp: 82−83 °C; H NMR (400 MHz, CDCl3) δ 1.27 (t, J =
7.1 Hz, 6H), 2.60 (t, J = 7.1 Hz, 4H), 2.72 (t, J = 7.8 Hz, 4H), 4.17
(q, J = 7.1 Hz, 4H), 7.28 (s, 4H); 13C NMR (100 MHz, CDCl3) δ
14.1, 15.3, 33.5, 60.6, 80.8, 89.6, 122.9, 131.3, 171.8. IR (KBr) νmax
3066, 2928, 2220, 1729, 1521, 1499 cm−1; MS m/z = 327 [M + H+].
Anal. Calcd for C20H22O4: C, 73.60; H, 6.79. Found: C, 73.48; H, 6.93.
Ethyl 5-(4-(2-(Trimethylsilyl)ethynyl)phenyl)pent-4-ynoate11
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(4ia). Yellow oil; H NMR (400 MHz, CDCl3) δ 0.24 (s, 9H), 1.28
(t, J = 7.1 Hz, 3H), 2.61 (t, J = 7.8 Hz, 2H), 2.73 (t, J = 7.8 Hz, 2H),
4.17 (q, J = 7.1 Hz, 2H), 7.30 (d, J = 8.5 Hz, 2H), 7.37 (d, J = 8.5 Hz,
2H). 13C NMR (100 MHz, CDCl3) δ −0.1, 14.2, 15.4, 29.8, 33.6, 60.7,
80.9, 90.1, 95.8, 104.7, 122.4, 123.7, 131.4, 131.7, 171.8. IR (KBr) νmax
3055, 2930, 2219, 1730, 1535, 1496 cm−1; MS m/z = 299 [M + H+].
Anal. Calcd for C18H22O2Si: C, 72.44; H, 7.43. Found: C, 72.58; H, 7.26.
Methyl 5-(4-Bromophenyl)-5-oxopentanoate (4db). Yellow
oil; 1H NMR (400 MHz, CDCl3) δ 2.03−2.09 (m, 2H), 2.44 (t, J = 7.2
Hz, 2H), 3.01 (t, J = 7.2 Hz, 2H), 3.67 (s, 3H), 7.59 (d, J = 8.7 Hz,
2H), 7.82 (d, J = 8.7 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 19.2,
29.7, 33.0, 37.4, 51.6, 128.2, 129.6, 131.9, 135.5, 173.6, 198.3. IR
(KBr) νmax 3066, 2952, 1736, 1687, 1586, 1484 cm−1; MS m/z =
286 [M + H+]. Anal. Calcd for C12H13BrO3: C, 50.55; H, 4.60. Found:
C, 50.73; H, 4.45.
Methyl 5-(4-Bromophenyl)-4-pentynoate (3db). Pale yellow
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oil; H NMR (400 MHz, CDCl3) δ 2.62 (t, J = 7.5 Hz, 2H), 2.71 (t,
J = 6.6 Hz, 2H), 3.71 (s, 3H), 7.23 (d, J = 8.6 Hz, 2H), 7.40 (d, J = 8.6
Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 15.3, 33.2, 51.8, 80.2, 89.2,
121.9, 122.5, 131.4, 133.0, 172.2; IR (KBr) νmax 3032, 2926, 2269,
1734, 1589, 1486 cm−1; MS m/z = 268 [M + H+]. Anal. Calcd for
C12H11BrO2: C, 53.96; H, 4.15. Found: C, 53.82; H, 4.38.
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Methyl 5-(3-Thienyl)-4-pentynoate (3fb). Yellow oil; H NMR
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(500 MHz, CDCl3) δ 2.63 (t, J = 7.2 Hz, 2H), 2.71 (t, J = 7.4 Hz, 2H),
3.72 (s, 3H), 7.06 (d, J = 4.8 Hz, 1H), 7.23 (dd, J = 4.5, 3.2 Hz, 1H),
7.36 (s, 1H); 13C NMR (125 MH7z, CDCl3) δ 15.3, 33.4, 51.8, 76.3,
87.5, 122.5, 125.0, 128.0, 129.9, 172.4; IR (KBr) νmax 3108, 2953,
2-Benzyl-5-ethylfuran (3ag). Yellow oil; H NMR (400 MHz,
CDCl3) δ 1.21 (t, J = 7.2 Hz, 3H), 2.60 (q, J = 7.5 Hz, 2H), 3.93
(s, 2H), 5.86 (s, 2H), 7.19−7.35 (m, 5H); 13C NMR (100 MHz,
CDCl3) δ 11.3, 21.6, 34.8, 104.8, 106.7, 127.1, 128.8, 128.9, 138.6, 152.7,
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dx.doi.org/10.1021/jo202628c | J. Org. Chem. 2012, 77, 3557−3562