Page 7 of 12
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The Journal of Organic Chemistry
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(ESI): calcd for C H BrO Na [M+Na] 345.0097, found
IC column, 10% IPA in hexane, rate: 1.0 mL/min, 254 nm).
Retention time: t (minor) = 13.4 min, t (major) = 20.1 min.
IR (KBr): νmax 2963, 2927, 1725, 1635, 1458, 1410, 1383, 1259,
1
5
15
3
345.0097.
R)-isopropyl-4-oxo-1(3(trifluoromethyl)phenyl)
pent-2-ene-1-carboxylate (3j). Colorless oil, 29.6 mg, yield:
(
cyclo-
−
1 1
1185, 1101, 1033, 916, 881, 797, 700 cm . H NMR (400 MHz,
25
CDCl , ppm): δ 7.95 (d, J = 5.7 Hz, 1H), 7.28-7.26 (m, 1H),
3
9
5%. R = 0.5 (petroleum ether/ethyl acetate 5:1), [α]
=
f
D
7
1
1
=
.12 (d, J = 7.5 Hz, 1H), 7.02-7.01 (m, 2H), 6.33 (d, J = 5.7 Hz,
H), 5.12-5.06 (m, 1H), 3.49 (d, J = 18.9 Hz, 1H), 2.59 (d, J =
8.9 Hz, 1H), 2.36 (s, 3H), 1.25 (d, J = 6.3 Hz, 3H), 1.20 (d, J
‒
11.1 (c = 0.63, CHCl ), 90% ee, determined by HPLC analy-
3
sis (chiralpak IC column, 10% IPA in hexane, rate: 1.0
mL/min, 254 nm). Retention time: t (minor) = 12.8 min, t
13
6.3 Hz, 3H). C NMR (100 MHz, CDCl , ppm): δ 207.6,
3
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
(
major) = 19.0 min. IR (KBr): νmax 3075, 2979, 2931, 1725,
1635, 1592, 1469, 1410, 1382, 1337, 1246, 1102, 1032, 997, 915,
1
71.3, 163.7, 141.0, 138.8, 133.8, 129.8, 128.4, 126.5, 122.9, 69.8,
60.0, 46.8, 21.6, 21.5, 21.4. HRMS (ESI): calcd for
−
1
1
876, 836, 793, 762, 695 cm . H NMR (400 MHz, CDCl ,
3
+
C H O Na [M+Na] 281.1148, found 281.1169.
1
6
18
3
ppm): δ 7.91 (d, J = 5.6 Hz, 1H), 7.46-7.44 (m, 1H), 7.37-7.36
(m, 1H), 7.28-7.23 (m, 1H), 7.16 (d, J = 7.8 Hz, 1H), 6.37 (d, J
= 5.6 Hz, 1H), 5.12-5.05 (m, 1H), 3.50 (d, J = 18.9 Hz, 1H),
(R)-isopropyl-4-oxo-1-(p-tolyl) cyclopent-2-ene-1 carbox-
ylate (3n). Colorless oil, 23.5 mg, yield: 91%. R = 0.6 (pe-
f
25
2.54 (d, J = 18.9 Hz, 1H), 1.25 (d, J =6.3 Hz, 3H), 1.21 (d, J =
troleum ether/ethyl acetate 5:1), [α]D = ‒8.5 (c = 0.22,
13
6
.3 Hz, 3H). C NMR (100 MHz, CDCl , ppm): δ 206.7,
CHCl ), 90% ee, determined by HPLC analysis (chiralpak
3
3
1
5
70.7, 162.4, 143.2, 134.5, 130.9, 130.6, 129.1, 124.6, 123.1, 70.2,
9.7, 46.6, 21.6, 21.4. HRMS (ESI): calcd for C H F O Na
IC column, 10% IPA in hexane, rate: 1.0 mL/min, 254 nm).
Retention time: t (minor) = 14.5 min, t (major) = 21.7 min.
IR (KBr): νmax 2963, 2923, 1725, 1635, 1512, 1458, 1409, 1382,
16 15
3
3
+
[
M+Na] 335.0866, found 335.0895.
(R)-isopropyl-4-oxo-1-(4-(trifluoromethyl) phenyl) cyclo-
pent-2-ene-1-carboxylate (3k). Colorless oil, 28.7 mg, yield:
−
1
1
1
260, 1101, 1026, 915, 871, 801 cm . H NMR (400 MHz,
CDCl , ppm): δ 7.95 (d, J = 5.6 Hz, 1H), 7.19-7.12 (m, 4H),
3
25
D
6.32 (d, J = 5.6 Hz, 1H), 5.11-5.05 (m, 1H), 3.48 (d, J = 18.9
Hz, 1H), 2.58 (d, J = 18.9 Hz, 1H), 2.35 (s, 3H), 1.25 (d, J =
92%. R = 0.5 (petroleum ether/ethyl acetate 5:1), [α]
‒38.5 (c = 0.50, CHCl ), 90% ee, determined by HPLC
analysis (chiralpak IC column, 10% IPA in hexane, rate: 1.0
mL/min, 254 nm). Retention time: t (minor) = 10.8 min, t
(
1
9
CDCl , ppm): δ 7.95 (d, J = 5.6 Hz, 1H), 7.64 (d, J = 8.3 Hz,
2
5
1
NMR (100 MHz, CDCl , ppm): δ 206.4, 170.9, 162.2, 145.0,
1
(
=
f
3
1
3
6
.3 Hz, 3H), 1.21 (d, J = 6.3 Hz, 3H). C NMR (100 MHz,
CDCl , ppm): δ 207.6, 171.4, 163.7, 138.1, 137.5, 133.7, 129.7,
3
1
25.7, 69.7, 59.7, 46.8, 21.6, 21.4, 21.0. HRMS (ESI): calcd
major) = 16.4 min. IR (KBr): νmax 3078, 2984, 2935, 1726,
+
for C H O Na [2M+Na] 539.2404, found 539.2403.
3
2
36
6
619, 1593, 1463, 1410, 1382, 1327, 1257, 1108, 1071, 1021, 986,
−
1
1
15, 874, 840, 799, 730, 675 cm . H NMR (400 MHz,
(R)-isopropyl-1-(4-(tert-butyl) phenyl)-4-oxocyclopent-2-
ene-1-carboxylate (3o). Colorless oil, 25.5 mg, yield: 85%. R
3
f
25
H), 7.36 (d, J = 8.2 Hz, 2H), 6.40 (d, J = 5.6 Hz, 1H), 5.14-
.04 (m, 1H), 3.54 (d, J = 18.8 Hz, 1H), 2.54 (d, J = 18.8 Hz,
= 0.6 (petroleum ether/ethyl acetate 6:1), [α]D = ‒8.4 (c =
0.43, CHCl ), 91% ee, determined by HPLC analysis (chi-
3
13
H), 1.25 (d, J = 6.3 Hz, 3H), 1.20 (d, J = 6.3 Hz, 3H).
C
ralpak IC column, 10% IPA in hexane, rate: 1.0 mL/min,
254 nm). Retention time: t (minor) = 11.7 min, t (major) =
17.0 min. IR (KBr): νmax 3081, 2963, 2870, 2069, 1726, 1593,
1510, 1463, 1407, 1383, 1261, 1186, 1103, 1027, 916, 872, 797,
3
34.7, 130.0 (q, J = 32.9 Hz), 126.4, 126.0 (q, J = 3.6 Hz), 123.8
q, J = 270.3 Hz), 70.3, 60.0, 46.5, 21.6, 21.4. HRMS (ESI):
+
−1 1
calcd for C H F O Na [M+Na] 335.0866, found 335.0863.
697 cm . H NMR (400 MHz, CDCl , ppm): δ 7.95 (d, J =
3
1
6
15
3
3
5
.6 Hz, 1H), 7.38 (d, J = 8.6 Hz, 2H), 7.15 (d, J = 8.6 Hz, 2H),
.32 (d, J = 5.6 Hz, 1H), 5.14-5.05 (m, 1H), 3.47 (d, J = 18.9
Hz, 1H), 2.62 (d, J = 18.9 Hz, 1H), 1.32 (s, 9H), 1.26 (d, J =
(
R)-isopropyl-4-oxo-1-(o-tolyl) cyclopent-2-ene-1 carbox-
6
ylate (3l). Colorless oil, 10.6 mg, yield: 41%. R = 0.6 (petro-
f
2
5
leum ether/ethyl acetate 5:1), [α]D = ‒87.3 (c = 0.25,
CHCl ), 78% ee, determined by HPLC analysis (chiralpak
IC column, 10% IPA in hexane, rate: 1.0 mL/min, 254 nm).
Retention time: t (minor) = 16.5 min, t (major) = 27.2 min.
IR (KBr): νmax 2964, 2924, 2854, 1725, 1641, 1456, 1409, 1382,
13
6
.3 Hz, 3H), 1.23 (d, J = 6.3 Hz, 3H). C NMR (100 MHz,
3
CDCl , ppm): δ 207.7, 171.4, 163.9, 150.6, 137.9, 133.5, 125.9,
3
1
25.5, 69.8, 59.7, 46.8, 34.5, 31.3, 21.6, 21.5. HRMS (ESI):
+
calcd for C H O Na [M+Na] 323.1618, found 323.1622.
1
9
24
3
−1
1
1
261, 1010, 1022, 868, 800, 744, 701 cm . H NMR (400 MHz,
(R)-isoproyl-1-(2-methoxyphenyl)-4-oxocyclopent-2 ene-
1-carboxylate (3p). Colorless oil, 26.0 mg, yield: 95%. R
CDCl , ppm): δ 7.94 (d, J = 5.6 Hz, 1H), 7.25-7.16 (m, 3H),
7
(
f
=
3
25
.07 (d, J = 7.5 Hz, 1H), 6.42 (d, J = 5.6 Hz, 1H), 5.09-5.03
m, 1H), 3.75 (d, J = 18.4 Hz, 1H), 2.34 (d, J = 18.4 Hz, 1H),
.25 (s, 3H), 1.23 (d, J =6.2 Hz, 3H), 1.16 (d, J = 6.2 Hz, 3H).
0.5 (petroleum ether/ethyl acetate 5:1), [α]
D
= ‒62.7 (c =
0.20, CHCl ), 80% ee, determined by HPLC analysis (chi-
3
2
ralpak IC column, 10% IPA in hexane, rate: 1.0 mL/min,
254 nm). Retention time: t (minor) = 34.5 min, t (major) =
36.5 min. IR (KBr): νmax 2923, 2854, 1725, 1634, 1500, 1460,
13
C NMR (100 MHz, CDCl , ppm): δ. 207.4, 171.6, 163.6,
3
1
2
2
40.5, 135.6, 134.8, 131.8, 127.6, 126.5, 126.0, 69.9, 60.4, 45.7,
+
−1
1
2.6, 21.5, 21.3. HRMS (ESI): calcd for C H O Na [M+Na]
1383, 1240, 1104, 1031, 804, 674 cm . H NMR (400 MHz,
1
6
18
3
81.1148, found 281.1140.
R)-isopropyl-4-oxo-1-(m-tolyl) cyclopent-2-ene-1 carbox-
CDCl , ppm): δ 7.83 (d, J = 5.6 Hz, 1H), 7.31-7.29 (m, 1H),
3
7
.06-7.03 (m, 1H), 6.96-6.38 (m, 2H), 6.38 (d, J = 5.6 Hz,
H), 5.06-5.00 (m, 1H), 3.81 (s, 3H), 3.64 (d, J = 18.9 Hz, 1H),
2.33 (d, J = 18.9 Hz, 1H), 1.20 (d, J =6.3 Hz, 3H), 1.14 (d, J =
(
1
ylate (3m). Colorless oil, 24.3 mg, yield: 94%. R = 0.6 (pe-
f
25
troleum ether/ethyl acetate 5:1), [α]D = ‒33.0 (c = 0.43,
CHCl ), 91% ee, determined by HPLC analysis (chiralpak
13
6.3 Hz, 3H). C NMR (100 MHz, CDCl , ppm): δ 208.3,
3
3
171.7, 162.8, 156.3, 135.1, 130.8, 128.9, 126.5, 120.5, 110.6, 69.2,
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