Synthesis of 3-Aryl-2,5-dihydro-1-benzoxepines
J. Chin. Chem. Soc., Vol. 55, No. 6, 2008 1319
6.68 (d, J = 8.0 Hz, 1H, ArH), 6.84 (t, J = 8.0 Hz, 1H, ArH),
7.01-7.14 (m, 2H, ArH), 7.33-7.55 (m, 3H, ArH), 7.90 (dd,
J = 8.8, 1.4 Hz, 2H, ArH); 13C-NMR (CDCl3, 50 MHz) d
34.22, 71.17, 111.61, 115.44, 121.49, 127.19, 128.14,
128.64, 129.12, 130.11, 133.63, 134.64, 136.76, 155.67,
194.73; EI-MS (70 eV) m/z (rel. intesity, %): 252 (M+, 2),
234 (6), 145 (13), 134 (9), 133 (100), 106 (9), 105 (56), 91
(12), 77 (23); HRMS (ESI), Calcd for C17H16O2Na:
275.1048. Found: 275.1049.
= 8.8 Hz, 2H, ArH), 13C-NMR (CDCl3, 50 MHz) d 34.15,
55.30, 70.93, 111.51, 113.75, 113.86, 115.35, 121.24,
127.10, 128.89, 129.91, 130.40, 136.72, 155.66, 163.78,
193.06; EI-MS (70 eV) m/z (rel. intesity, %) 282 (M+, 0.5),
150 (28), 136 (9), 135 (100), 133 (14), 121 (6), 107 (6), 77
(16); HRMS (ESI), Calcd for C18H18O3Na: 305.1154.
Found: 305.1153.
General procedure for the preparation of 1-aryloxy-
2-phenyl-1-propenes (4a-d)
2-(2-Allylphenoxy)-1-(4-chlorophenyl)ethanone (3b)
(6.6 g, 93%) was obtained as pale yellow liquid, Rf =
0.49 (ethyl acetate: n-hexane = 1: 10), 1H-NMR (CDCl3,
400 MHz) d 3.43 (d, J = 6.4 Hz, 2H, ArCH2CH=CH2), 5.00-
5.05 (m, 2H, ArCH2CH=CH2), 5.17 (s, 2H, ArOCH2CO),
5.93-6.03 (m, 1H, ArCH2CH=CH2), 6.75 (d, J = 7.8 Hz,
1H, ArH), 6.92 (td, J = 7.8, 0.8 Hz, 1H, ArH), 7.11-7.17 (m,
2H, ArH), 7.43 (d, J = 8.4 Hz, 2H, ArH), 7.93 (d, J = 8.4
Hz, 2H, ArH), 13C-NMR (CDCl3, 100 MHz) d 34.16,
71.13, 111.42, 115.56, 121.60, 127.26, 128.98, 129.71,
130.21, 132.86, 136.67, 140.14, 155.48, 193.89, EI-MS
(70 eV) m/z (rel. intesity, %) 288 ([M+2]+, 0.5), 286 (M+,
1.5), 141 (44), 140 (21), 139 (100), 134 (91), 133 (44), 132
(70), 130 (25); HRMS (ESI), Calcd for C17H15ClO2Na:
309.0658. Found: 309.0657.
Under the protection of N2, the suspension of MTPPB
(9.0 g, 25.2 mmol) in THF (100 mL) was cooled in ice-bath
and was added t-BuOK (3.03 g, 27.0 mmol) in portions.
Then, the reaction mixture was stirred at 0 °C for 30 min.
To this cooled solution, 3a-e (20.0 mmol) in THF (40 mL)
was added in drops and stirred for 4 hr. Then, the resulting
mixture was quenched with water and extracted with
CH2Cl2 (50 mL ´ 5). The organic layer was combined and
washed with brine (50 mL ´ 2), and then was concentrated
in vacuo to give crude 4a-d which was further purified
from silica gel column chromatography (ethyl acetate: n-
hexane = 1: 10) to give pure 4a-d.
1-Allyl-2-(2-phenylallyloxy)benzene (4a)
(4.51 g, 90%) was obtained as pale yellow liquid, Rf
= 0.68 (ethyl acetate: n-hexane = 1: 10), 1H-NMR (CDCl3,
200 MHz) d 3.62 (d, J = 6.6 Hz, 2H, ArCH2CH=CH2), 5.10
(s, 2H, ArOCH2), 5.20-5.30 (m, 2H, ArCH2CH=CH2), 5.72
(d, J = 1.2 Hz, 1H, ArOCH2C=CHaHb), 5.82 (d, J = 1.2 Hz,
1H, ArOCH2C=CHaHb), 6.09-6.29 (m, 1H, ArCH2CH=CH2),
7.11-7.19 (m, 2H, ArH), 7.38-7.41 (m, 2H, ArH), 7.53-
7.61 (m, 3H, ArH), 7.67-7.72 (m, 2H, ArH), 13C-NMR
(CDCl3, 50 MHz) d 34.39, 69.72, 111.64, 114.21, 115.29,
120.80, 126.03, 127.19, 127.87, 128.37, 129.03, 129.85,
136.89, 138.47, 143.31, 156.11; EI-MS (70 eV) m/z (rel.
intesity, %) 250 (M+, 11), 209 (25), 133 (24), 132 (71), 131
(55), 117 (44), 115 (100), 91 (41); HRMS (EI), Calcd for
C18H18O: 250.1358. Found: 250.1361.
2-(2-Allylphenoxy)-1-(4-bromophenyl)ethanone (3c)
(7.6 g, 92%) was obtained as colorless crystal, mp
85~86 °C, Rf = 0.46 (ethyl acetate: n-hexane = 1: 10),
1H-NMR (CDCl3, 400 MHz) d 3.43 (d, J = 6.4 Hz, 2H,
ArCH2CH=CH2), 5.00-5.05 (m, 2H, ArCH2CH=CH2), 5.17
(s, 2H, ArOCH2CO), 5.30-6.30 (m, 1H, ArCH2CH=CH2),
6.75 (d, J = 8.4 Hz, 1H, ArH), 6.93 (td, J = 7.2, 0.8 Hz, 1H,
ArH), 7.12-7.17 (m, 2H, ArH), 7.61 (d, J = 8.8 Hz, 2H,
ArH), 7.86 (d, J = 8.8 Hz, 2H, ArH), 13C-NMR (CDCl3,
100 MHz) d 34.19, 71.19, 111.47, 115.58, 121.66, 127.30,
128.96, 129.02, 129.83, 130.25, 132.01, 133.32, 136.70,
155.52, 194.15, EI-MS (70 eV) m/z (rel. intesity, %) 332
([M+2]+, 0.5), 330 (M+, 0.5), 185 (17), 183 (18), 134 (17),
133 (100), 131 (11), 105 (18), 91 (15); HRMS (ESI), Calcd
for C17H15BrO2Na: 353.0153. Found: 353.0155.
1-Allyl-2-[(2-(4-chlorophenyl)allyloxy)]benzene (4b)
(4.65 g, 91%) was obtained as pale yellow liquid, Rf =
0.66 (ethyl acetate: n-hexane = 1: 10), 1H-NMR (CDCl3,
200 MHz) d 3.45 (d, J = 6.6 Hz, 2H, ArCH2CH=CH2), 4.95
(s, 2H, ArOCH2), 5.06-5.13 (m, 2H, ArCH2CH=CH2) 5.59
(d, J = 1.0 Hz, 1H, ArOCHC=CHaCHb), 5.68 (d, J = 1.0 Hz,
1H, ArOCHC=CHaCHb), 5.92-6.13 (m, 1H, ArCH2CH=CH2),
6.98-7.07 (m, 2H, ArH), 7.25-7.36 (m, 2H, ArH), 7.38-
7.52 (m, 4H, ArH), 13C-NMR (CDCl3, 50 MHz) d 34.32,
69.53, 111.52, 114.98, 115.36, 120.93, 126.45, 127.21,
127.35, 128.49, 128.94, 129.93, 133.72, 136.77, 142.25,
2-(2-Allylphenoxy)-1-(4-methoxyphenyl)ethanone (3d)
(6.5 g, 92%) was obtained as pale yellow liquid, Rf =
0.27 (ethyl acetate: n-hexane = 1: 10), 1H-NMR (CDCl3,
200 MHz) d 3.45 (d, J = 6.6 Hz, 2H, ArCH2CH=CH2), 3.81
(s, 3H, ArOCH3), 5.00-5.05 (m, 2H, ArCH2CH=CH2), 5.16
(s, 2H, ArOCH2CO), 5.91-6.11 (m, 1H, ArOCH2CH=CH2),
6.75 (d, J = 8.2 Hz, 1H, ArH), 6.86-6.90 (m, 1H, ArH), 6.91
(d, J = 8.8 Hz, 2H, ArH), 7.05-7.16 (m, 2H, ArH), 7.96 (d, J