G. A. Molander et al. / Tetrahedron 63 (2007) 768–775
773
d 8.04 (d, 2H, J¼7.3 Hz), 7.54 (t, 1H, J¼7.5 Hz), 7.43 (m,
4.3.1.11. 6-(2-Methyl-5-oxocyclopent-1-enyl)hexane-
nitrile (24). The title compound was obtained as a pale
yellow oil (16.5 mg, 86% yield) using 2-bromo-3-methyl-
4
H), 7.33 (t, 2H, J¼8 Hz), 7.25 (t, 1H, J¼8.6 Hz), 5.32
(
s, 1H), 5.11 (s, 1H), 4.34 (t, 2H, J¼6.5 Hz), 2.68 (t,
1
3
2 C NMR
125.8 MHz, CDCl ) d 166.6, 147.2, 140.8, 132.8, 130.4,
H, J¼7.5 Hz), 1.94 (p, 2H, J¼6.7 Hz).
2-cyclopenten-1-one and potassium 5-cyanopentyltrifluoro-
borate (13). H NMR (500 MHz, CDCl ) d 2.50 (m, 2H),
1
(
3
3
1
FTIR (neat) n 3059, 2955, 1718, 1601, 1493, 1451,
29.5, 128.4, 128.3, 127.5, 126.1, 113.0, 64.3, 31.7, 27.2.
2.36 (m, 2H), 2.33 (t, 2H, J¼7.1 Hz), 2.19 (m, 2H), 2.05
1
3
(s, 3H), 1.66 (m, 2H), 1.43 (m, 4H). C NMR (125.8 MHz,
CDCl ) d 209.9, 170.7, 140.4, 120.0, 34.6, 31.9, 28.8, 27.7,
ꢁ
1
1
(
314, 1274, 1115, 1070, 1026, 900, 778, 710 cm . HRMS
CI): m/z calcd for C H O [M+H] 267.1385, found
3
+
25.5, 23.0, 17.6, 17.4. FTIR (neat) n 2935, 2860, 2244, 1694,
1644, 1442, 1386, 1340, 1178, 1076 cm . HRMS (CI): m/z
1
8 19 2
ꢁ
1
2
67.1372.
+
calcd for C H NO [M+H] 192.1388, found 192.1387.
12 18
4.3.1.7. 4,5,5-Triphenylpent-4-enyl benzoate (9). The
title compound was obtained as a white solid (38.1 mg,
4.3.1.12. 2-(5-Bromopentyl)-3-methylcyclopent-2-
enone (25). The title compound was obtained as a colorless
9
1% yield) using bromotriphenylethylene and potassium
ꢀ
(
3-benzoyloxy)propyltrifluoroborate (3). Mp¼89–91 C.
oil (17 mg, 69% yield) using 2-bromo-3-methyl-2-cyclo-
penten-1-one and potassium 5-bromopentyltrifluoroborate
1
H NMR (500 MHz, CDCl ) d 7.91 (d, 2H, J¼7.4 Hz),
3
1
7
.54 (t, 1H, J¼7.4 Hz), 7.40 (t, 2H, J¼7.6 Hz), 7.29–7.20
(14). H NMR (500 MHz, CDCl ) d 3.39 (t, 2H, J¼6.7 Hz),
3
(
m, 5H), 7.18–7.11 (m, 5H), 7.00 (m, 3H), 6.88 (m, 2H),
.19 (t, 2H, J¼6.3 Hz), 2.63 (m, 2H), 1.80 (m, 2H).
2.49 (m, 2H), 2.36 (m, 2H), 2.18 (m, 2H), 2.05 (s, 3H), 1.87
(m, 2H), 1.41 (m, 4H). C NMR (125.8 MHz, CDCl ) d
1
3
4
3
1
3
C NMR (125.8 MHz, CDCl ) d 166.5, 143.2, 142.6,
3
209.7, 170.3, 140.3, 34.3, 33.8, 32.5, 31.5, 28.0, 27.4, 22.8,
17.2. FTIR (neat) n 2934, 2858, 1697, 1645, 1439, 1385,
1
1
6
1
9
41.8, 140.2, 139.4, 132.8, 130.6, 130.3, 129.6 (2C),
29.3, 128.3, 128.2, 128.0, 127.4, 126.6, 126.4, 125.9,
4.7, 32.5, 28.0. FTIR (neat) n 3055, 3020, 2957, 1718,
599, 1491, 1451, 1443, 1314, 1274, 1117, 1070, 1027,
ꢁ
1
1299, 1177, 1073, 938 cm . HRMS (CI): m/z calcd for
C H OBr [M+H] 245.0541, found 245.0529.
+
1
1 18
ꢁ
1
10, 763, 700 cm . HRMS (CI): m/z calcd for C H O
0 26 2
4.3.1.13. 3-Methyl-2-(5-oxohexyl)cyclopent-2-enone
(26). The title compound was obtained as a yellow oil
16.8 mg, 87% yield) using 2-bromo-3-methyl-2-cyclo-
3
+
[
M] 418.1933, found 418.1932.
(
4
.3.1.8. 2-Ethyl-3-methylcyclopent-2-enone (21). The
title compound was obtained as a colorless oil (10.3 mg,
3% yield) using 2-bromo-3-methyl-2-cyclopenten-1-
penten-1-one and potassium (5-oxo)hexyltrifluoroborate
(15). H NMR (500 MHz, CDCl ) d 2.49 (m, 2H), 2.43 (t,
1
3
8
2H, J¼7.4 Hz), 2.36 (m, 2H), 2.18 (t, 2H, J¼7.6 Hz), 2.12
1
one and potassium ethyltrifluoroborate (10). H NMR
500 MHz, CDCl ) d 2.48 (m, 2H), 2.36 (m, 2H), 2.19 (q,
(s, 3H), 2.05 (s, 3H), 1.54 (p, 2H, J¼7.6 Hz), 1.38 (m,
1
3
(
2H). C NMR (125.8 MHz, CDCl ) d 209.7, 209.0, 170.5,
3
3
2
H, J¼7.6 Hz), 2.05 (s, 3H), 0.97 (t, 3H, J¼7.6 Hz).
140.1, 43.4, 34.3, 31.5, 29.9, 27.7, 23.6, 22.7, 17.2. FTIR
1
3
C NMR (125.8 MHz, CDCl ) d 209.6, 169.6, 142.0,
3
(neat) n 2932, 2860, 1711, 1696, 1644, 1441, 1385, 1359,
ꢁ
1178, 1072 cm . HRMS (CI): m/z calcd for C H O
12 18 2
1
34.4, 31.5, 17.0, 16.2, 12.9. FTIR (neat) n 2966, 2928,
1697, 1646, 1443, 1385, 1348, 1178, 1056, 935 cm
ꢁ
1
+
.
[M] 194.1307, found 194.1306.
+
HRMS (CI): m/z calcd for C H O [M] 124.0888, found
8
12
1
24.0895.
4.3.1.14. Methyl 6-(2-methyl-5-oxocyclopent-1-enyl)-
hexanoate (27). The title compound was obtained as
a pale yellow oil (14.1 mg, 63% yield) using 2-bromo-3-
4.3.1.9. 3-Methyl-2-[(trimethylsilyl)methyl]cyclopent-
-enone (22). The title compound was obtained as a colorless
2
oil (17.3 mg, 95% yield) using 2-bromo-3-methyl-2-cyclo-
methyl-2-cyclopenten-1-one and potassium methyl 6-(tri-
fluoroborato)hexanoate (16). H NMR (500 MHz, CDCl )
1
3
penten-1-one and potassium (trimethylsilyl)methyltri-
fluoroborate (11). H NMR (500 MHz, CDCl ) d 2.46 (m,
d 3.66 (s, 3H), 2.49 (m, 2H), 2.35 (m, 2H), 2.29 (t, 2H,
J¼7.5 Hz), 2.16 (t, 2H, J¼7.3 Hz), 2.04 (s, 3H), 1.62 (p,
1
3
1
3
2
9
3
1
8
H), 2.34 (m, 2H), 1.97 (s, 3H), 1.60 (s, 2H), ꢁ0.03 (s,
2H, J¼7.6 Hz), 1.38 (m, 2H), 1.30 (m, 2H). C NMR
13
H). C NMR (125.8 MHz, CDCl ) d 209.2, 165.6, 138.6,
3
(125.8 MHz, CDCl ) d 209.7, 174.2, 170.2, 140.4, 51.4,
3
4.1, 31.4, 17.7, 13.3, ꢁ1.0. FTIR (neat) n 2954, 2913,
34.3, 34.0, 31.7, 29.1, 28.0, 24.7, 22.8, 17.2. FTIR (neat) n
2931, 2858, 1736, 1697, 1644, 1437, 1385, 1175 cm .
ꢁ
1
697, 1441, 1409, 1383, 1329, 1248, 1181, 1161, 1068,
41, 694 cm . HRMS (CI): m/z calcd for C H OSi
ꢁ1
+
HRMS (CI): m/z calcd for C H O [M] 224.1412, found
13 20 3
1
0
18
+
[
M] 182.1127, found 182.1132.
224.1405.
4
.3.1.10. 3-Methyl-2-octylcyclopent-2-enone (23). The
title compound was obtained as a pale yellow oil (11.1 mg,
3% yield) using 2-bromo-3-methyl-2-cyclopenten-1-one
4.3.1.15. 2-(3,4-Dihydroxybutyl)-3-methylcyclopent-
2-enone (28). The title compound was obtained as a brown
oil (17.3 mg, 94% yield) using 2-bromo-3-methyl-2-cyclo-
5
1
and potassium octyltrifluoroborate (12). H
(500 MHz, CDCl ) d 2.48 (m, 2H), 2.35 (m, 2H), 2.16 (t,
NMR
penten-1-one and potassium 3,4-dihydroxybutyltrifluoro-
borate (17). H NMR (500 MHz, CDCl ) d 3.78 (br s,
1
3
3
2
0
H, J¼7.4 Hz), 2.04 (s, 3H), 1.35 (m, 2H), 1.26 (m, 10H),
1H, –OH), 3.55 (m, 1H), 3.45 (m, 2H), 2.54 (m, 2H), 2.41
(m, 2H), 2.38–2.30 (m, 2H), 2.09 (s, 3H), 1.53 (m, 1H),
1.40 (m, 1H), missing –OH. C NMR (125.8 MHz,
1
3
.87 (t, 3H, J¼6.7 Hz). C NMR (125.8 MHz, CDCl )
3
1
3
d 209.7, 170.2, 140.8, 34.3, 31.8, 31.5, 29.6, 29.4, 29.2,
2
1
8.4, 23.0, 22.6, 17.2, 14.1. FTIR (neat) n 2925, 2855,
701, 1648, 1442, 1385, 1339, 1177, 1073 cm . HRMS
CDCl ) d 211.5, 172.7, 139.9, 70.4, 66.6, 34.2, 31.8, 31.7,
3
ꢁ
1
18.3, 17.2. FTIR (neat) n 3400, 2922, 1680, 1637, 1439,
1388, 1348, 1179, 1047, 865 cm . HRMS (CI): m/z calcd
+
ꢁ1
(
CI): m/z calcd for C H O [M+H] 209.1905, found
1
4 25
+
2
09.1903.
for C H O [M+H] 185.1178, found 185.1171.
10 17 3