The Journal of Organic Chemistry
ARTICLE
7.62À7.52 (m, 1H), 7.32À7.27 (m, 1H), 7.25À7.21 (m, 1H),
7.12À7.02 (m, 4H), 6.80 (dd, J = 9.2, 1.4 Hz, 1H), 4.93À4.71
(m, 3H), 3.95 (s, 3H), 3.79 (s, 3H); 13C NMR (100 MHz,
134.8, 132.5, 131.4, 129.3, 128.2, 127.5, 120.4, 118.9, 117.8,
112.1, 78.2, 66.4, 56.0, 41.1; IR (thin film) ν/cmÀ1 2360, 1732,
1640, 1555, 1120; HRMS (ESI) calcd for C22H21NO7 (M À
CDCl3) δ 163.4, 161.8, 160.0, 140.6, 134.9, 132.6, 130.1 (d, J(CF)
=
H)À 410.1240, found 410.1232; [R]20 = À91.0 (c = 1.0,
D
8.4 Hz), 129.9 (d, J(CF) = 4.2 Hz), 125.7 (d, J(CF) = 1.9 Hz), 124.9
(d, J(CF) = 3.4 Hz), 123.6 (d, J(CF) = 13.6 Hz), 120.3, 117.6,
116.4, 116.2, 112.1, 76.9 (d, J(CF) = 3.3 Hz), 56.0, 52.7, 36.8; IR
(thin film) ν/cmÀ1 2955, 1735, 1556, 1492, 1297, 1230, 756;
HRMS (ESI) calcd for C20H18FNO7 (M À H)À 402.0989,
CH2Cl2); enantiomeric excess was determined by HPLC with
Chiralpak IC column (hexane/i-PrOH = 60:40, 1.0 mL/min,
230 nm), tr(minor) = 9.7 min, tr(major) = 12.0 min, 96% ee.
(R,Z)-1-Isopropoxy-5-nitro-1-oxo-4-phenylpent-2-en-2-yl
2-Methoxybenzoate (5m). Colorless oil (35.1 mg, yield 85%).
1H NMR (400 MHz, CDCl3) δ 7.95À7.87 (m, 1H), 7.61À7.51
(m, 1H), 7.38À7.26 (m, 5H), 7.11À6.99 (m, 2H), 6.65 (d, J =
9.2 Hz, 1H), 5.15À5.02 (m, 1H), 4.84À4.74 (m, 2H), 4.74À4.66
(m, 1H), 3.95 (s, 3H), 1.26 (dd, J = 6.2, 2.0Hz, 6H); 13C NMR
(100 MHz, CDCl3) δ 163.7, 160.9, 159.7, 140.6, 136.9, 134.6,
132.3, 129.3, 128.2, 127.5, 126.5, 120.3, 118.1, 112.1, 78.2, 69.9,
56.0, 41.0, 21.7; IR (thin film) ν/cmÀ1 2983, 1725, 1556, 1293,
756, 700; HRMS (ESI) calcd for C22H23NO7 (M À H)À
412.1396, found 412.1393; [R]20D = À83.1 (c = 1.0, CH2Cl2);
enantiomeric excess was determined by HPLC with Chiralpak
IC column (hexane/i-PrOH = 60:40, 1.0 mL/min, 230 nm),
tr(minor) = 8.3 min, tr(major) = 9.3 min, 97% ee.
found 402.0982; [R]20 = À72.7 (c = 1.0, CH2Cl2); enantio-
D
meric excess was determined by HPLC with Chiralpak IC column
(hexane/i-PrOH = 60:40, 1.0 mL/min, 230 nm), tr(minor) =
11.2 min, tr(major) = 20.2 min, 93% ee.
(R,Z)-4-(3-Chlorophenyl)-1-methoxy-5-nitro-1-oxopent-2-
en-2-yl 2-Methoxybenzoate (5i). Colorless oil (41.5 mg, yield
1
99%). H NMR (400 MHz, CDCl3) δ 7.98À7.90 (m, 1H),
7.61À7.55 (m, 1H), 7.29À7.26 (m, 3H), 7.19À7.11 (m, 1H),
7.09À7.02 (m, 2H), 6.67 (d, J = 9.4 Hz, 1H), 4.80À4.72
(m, 2H), 4.72À4.60 (m, 1H), 3.96 (s, 3H), 3.79 (s, 3H); 13C
NMR (100 MHz, CDCl3) δ 163.4, 161.7, 160.0, 140.4 138.7,
135.1, 135.0, 132.6, 130.6, 128.5, 127.8, 126.4, 125.6, 120.4,
117.4, 112.1, 77.8, 56.0, 52.8, 40.7; IR (thin film) ν/cmÀ1 1734,
1556, 1294, 756, 696; HRMS (ESI) calcd for C20H18ClNO7
(M À H)À 418.0694, found 418.0694; [R]20D = À87.8 (c = 1.0,
CH2Cl2); enantiomeric excess was determined by HPLC with
Chiralpak IC column (hexane/i-PrOH = 60:40, 1.0 mL/min,
230 nm), tr(minor) = 13.8 min, tr(major) = 25.1 min, 93% ee.
(S,Z)-1-Methoxy-5-nitro-1-oxo-4-(thiophen-2-yl)pent-2-en-
2-yl 2-Methoxybenzoate (5j). Colorless oil (38.7 mg, yield 99%).
1H NMR (400 MHz, CDCl3) δ 8.01À7.93 (m, 1H), 7.62À7.53
(m, 1H), 7.26À7.23 (m, 1H), 7.11À7.01 (m 2H), 6.98À6.93
(m, 2H), 6.69 (d, J = 9.8 Hz, 1H), 5.06À4.95 (m, 1H),
4.83À4.63 (m, 2H), 3.95 (s, 3H), 3.80 (s, 3H); 13C NMR
(100 MHz, CDCl3) δ 163.5, 161.8, 160.0, 140.2, 138.9, 135.0,
132.7, 127.4, 126.5, 125.7, 125.4, 120.4, 117.5, 112.1, 78.6, 56.0,
52.8, 36.3; IR (thin film) ν/cmÀ1 1734, 1556, 1296, 1229, 1122,
756, 705; HRMS (ESI) calcd for C18H17NO7S (M À H)À
390.0647, found 390.0640; [R]20D = À66.5 (c = 1.0, CH2Cl2);
enantiomeric excess was determined by HPLC with Chiralpak IC
column (hexane/i-PrOH = 60:40, 1.0 mL/min, 230 nm), tr-
(minor) = 14.0 min, tr(major) = 21.6 min, 95% ee.
(S,Z)-1-Ethoxy-5-methyl-4-(nitromethyl)-1-oxohex-2-en-2-yl
2-Methoxybenzoate (5n). Colorless oil (31.0 mg, yield 85%). 1H
NMR (400 MHz, CDCl3) δ 7.99À7.92 (m, 1H), 7.59À7.51 (m,
1H), 7.07À6.99 (m, 2H), 6.45 (d, J = 10.6 Hz, 1H), 4.54 (dd, J =
12.4, 6.6 Hz, 1H), 4.43 (dd, J = 12.4, 7.6 Hz, 1H), 4.30À4.23 (m,
2H), 3.93 (s, 3H), 3.32 (ddt, J = 10.6, 7.6, 6.6 Hz, 1H), 1.94À1.81
(m, 1H), 1.29 (t, J = 7.2 Hz, 3H), 0.99 (d, J = 6.8 Hz, 6H); 13C
NMR (100 MHz, CDCl3) δ 163.6, 161.4, 160.0, 141.6, 134.7,
132.5, 126.4, 120.3, 118.0, 112.1, 61.8, 56.0, 41.4, 29.7, 20.4, 18.6,
14.1; IR (thin film) ν/cmÀ1 2964, 2921, 2383, 1729, 1601, 1297,
1255, 1095, 758; HRMS (ESI) calcd for C18H23NO7 (M À H)À
364.1396, found 364.1391; [R]20 = À2.4 (c = 1.0, CH2Cl2);
D
enantiomeric excess was determined by HPLC with Chiralpak IC
column (hexane/i-PrOH = 60:40, 1.0 mL/min, 230 nm),
tr(minor) = 10.8 min, tr(major) = 14.3 min, 91% ee.
(S,Z)-4-Cyclohexyl-1-ethoxy-5-nitro-1-oxopent-2-en-2-yl
2-Methoxybenzoate (5o). Colorless oil (33.2 mg, yield 82%). 1H
NMR (400 MHz, CDCl3) δ 7.99À7.91 (m, 1H), 7.59À7.49
(m, 1H), 7.08À6.98 (m, 2H), 6.46 (d, J = 10.8 Hz, 1H), 4.56 (dd,
J = 12.4, 6.4 Hz, 1H), 4.43 (dd, J = 12.4, 7.8 Hz, 1H), 4.30À4.21
(m, 2H), 3.93 (s, 3H), 3.39À3.21 (m, 1H), 1.73À1.45 (m, 5H),
1.29 (t, J = 7.2 Hz, 3H), 1.23À0.82 (m, 6H); 13C NMR
(100 MHz, CDCl3) δ 163.6, 161.4, 160.0, 141.4, 134.7, 132.5,
127.1, 120.3, 118.0, 112.1, 76.8, 61.8, 56.0, 40.9, 39.4, 30.8, 29.2,
26.1, 26.0, 26.0, 14.1; IR (thin film) ν/cmÀ1 2929, 2854, 1729,
1555, 1295, 756; HRMS (ESI) calcd for C21H27NO7 (M À H)À
404.1709, found 404.1700; [R]20D = À18.2 (c = 1.0, CH2Cl2);
enantiomeric excess was determined by HPLC with Chiralpak
IC column (hexane/i-PrOH = 60:40, 1.0 mL/min, 230 nm),
tr(minor) = 12.6 min, tr(major) = 15.5 min, 91% ee.
(R,Z)-1-Ethoxy-5-nitro-1-oxo-4-phenylpent-2-en-2-yl 2-Meth-
oxybenzoate (5k). Colorless oil (33.1 mg, yield 83%). 1H NMR
(400 MHz, CDCl3) δ 7.99À7.92 (m, 1H), 7.59À7.50 (m, 1H),
7.38À7.26 (m, 5H), 7.10À6.97 (m, 2H), 6.69 (d, J = 9.4 Hz,
1H), 4.83À4.75 (m, 2H), 4.74À4.66 (m, 1H), 4.32À4.18 (m,
2H), 3.96 (s, 3H), 1.28 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz,
CDCl3) δ 163.7, 161.4, 159.9, 140.3, 136.8, 134.8, 132.5, 129.3,
128.2, 127.5, 127.0, 120.3, 117.9, 112.1, 78.2, 61.9, 56.0, 41.0,
14.1; IR (thin film) ν/cmÀ1 2982, 1728, 1556, 1294, 1228, 1124,
1083, 756, 700; HRMS (ESI) calcd for C21H21NO7 (M À H)À
398.1240, found 398.1237; [R]20D = À91.8 (c = 1.0, CH2Cl2);
enantiomeric excess was determined by HPLC with Chiralpak IC
column (hexane/i-PrOH = 60:40, 1.0 mL/min, 230 nm), tr-
(minor) = 10.9 min, tr(major) = 14.3 min, 96% ee.
(R,Z)-1-(Allyloxy)-5-nitro-1-oxo-4-phenylpent-2-en-2-yl 2-Meth-
oxybenzoate (5l). Colorless oil (34.9 mg, yield 85%). 1H NMR
(400 MHz, CDCl3) δ 7.97À7.90 (m, 1H), 7.62À7.52 (m, 1H),
7.37À7.26 (m, 5H), 7.10À6.98 (m, 2H), 6.72 (d, J = 9.2 Hz,
1H), 5.98À5.81 (m, 1H), 5.37À5.18 (m, 2H), 4.83À4.75 (m,
2H), 4.74À4.70 (m, 1H), 4.70À4.66 (m, 2H), 3.95 (s, 3H); 13C
NMR (100 MHz, CDCl3) δ 163.6, 161.1, 159.9, 140.0, 136.7,
(4R,5R/5S,Z)-1-Methoxy-5-nitro-1-oxo-4-p-tolylhex-2-en-2-yl
Benzoate (3n). Colorless oil (21.8 mg, yield 57%), a mixture of
1
two diastereoisomers. H NMR (400 MHz, CDCl3) δ 8.16À
8.07 (m, 2H + 0.8H*), 7.74À7.61 (m, 1H + 0.4H*), 7.58À7.44
(m, 2H + 0.8H*), 7.16À7.06 (m, 4H + 1.6H*), 6.85 (d, J = 10.0 Hz,
0.4H*), 6.69 (d, J = 10.6 Hz, 1H), 5.06À4.83 (m, 1H + 0.4H*),
4.24 (t, J = 10.2 Hz, 1H), 4.15 (t, J = 9.8 Hz, 0.4H*), 3.77 (s, 3H),
3.76 (s, 1.2H*), 2.31 (s, 1.2H*), 2.30 (s, 3H), 1.63 (d, J = 6.8 Hz,
3H), 1.39 (d, J = 6.8 Hz, 1.2H*); 13C NMR (100 MHz, CDCl3)
δ 164.2, 161.8, 140.2, 138.1, 134.1, 133.6, 130.4, 129.9, 128.8,
128.1, 127.9, 127.5, 86.3, 52.7, 47.0, 21.0, 18.1; IR (thin film)
6237
dx.doi.org/10.1021/jo2009752 |J. Org. Chem. 2011, 76, 6230–6239