A New Synthesis of Benzofurans
J. Chin. Chem. Soc., Vol. 51, No. 6, 2004 1315
128.69, 149.12, 153.03; EI-MS (70 eV), m/z 160 (M+, 42),
145 (46), 131 (84), 118 (50), 117 (96), 115 (100), 103 (50), 91
(70), 84 (69), 77 (56), 63 (52), 51 (85), 49 (48), 47 (56);
HRMS: Calcd for C11H12O: 160.0883. Found: 160.0881.
63 (56); HRMS: Calcd for C11H11ClO: 194.0493. Found:
194.0497.
1-(2-Propenyl-3-vinyloxyphenyl)-ethanone (5e)
Pure 5e (0.90 g, 89%) was obtained as pale yellow liq-
1
4-Methyl-2-(1-propenyl)-1-vinyloxybenzene (5b)
uid, Rf = 0.73 (EA: Hexane = 1:4), H-NMR (CDCl3, 200
Pure 5b (0.79 g, 90%) was obtained as liquid: Rf =
0.675 (ethyl acetate: n-hexane = 1:20), 1H-NMR (CDCl3, 400
MHz) d 1.90 (dd, J = 6.4 Hz, 1.6 Hz, 3H, ArCH=CHCH3),
2.30 (s, 3H, ArCH3), 4.33 (dd, J = 6.0 Hz, 1.6 Hz, 1H,
OCH=CH2), 4.62 (dd, J = 14.0 Hz, 1.6 Hz, 1H, OCH=CH2),
6.23 (dq, J = 16.0 Hz, 6.4 Hz, 1H, ArCH=CHCH3), 6.58 (dd, J
= 14.0 Hz, 6.0 Hz, 1H, OCH=CH2), 6.64 (dq, J = 16.0 Hz, 1.6
Hz, 1H, ArCH=CHCH3), 6.83 (d, J = 8.4 Hz, 1H, H-6), 6.99
(dd, J = 8.4 Hz, 1.8 Hz, 1H, H-5), 7.34 (d, J = 1.8 Hz, 1H,
H-3); 13C-NMR (CDCl3, 100 MHz) d 18.81, 20.72, 93.27,
117.78, 124.95, 126.75, 126.81, 128.23, 128.37, 132.92,
149.54, 150.88; EI-MS (70 eV), m/z 174 (M+, x2), HRMS:
Calcd for C12H14O: 174.1039. Found: 174.1043.
MHz) d 1.89 (dd, J = 6.6 Hz, 1.8 Hz, 3H, ArCH=CHCH3),
2.43 (s, 3H, ArCOCH3), 4.44 (dd, J = 6.0 Hz, 2.0 Hz, 1H,
ArOCH=CH2), 4.69 (dd, J = 13.6 Hz, 2Hz, 1H, ArOCH=CH2),
5.88 (dq, J = 16.0 Hz, 6.6 Hz, 1H, ArCH=CHCH3), 6.57 (dd, J
= 13.6 Hz, 6.0 Hz, 1H, ArOCH=CH2), 6.61 (dq, J = 16.0 Hz,
1.8 Hz, 1H, ArCH=CHCH3), 7.04 (dd, J = 7.6 Hz, 1.4 Hz, 1H,
H-4), 7.11 (dd, J = 7.6 Hz, 1.4 Hz, 1H, H-6), 7.23 (t, J = 7.6
Hz, 1H, H-5); 13C-NMR (CDCl3, 50 MHz) d 19.27, 30.73,
95.07, 119.03, 122.34, 123.91, 123.35, 127.59, 133.94, 142.35,
148.48, 153.90, 204.77; EI-MS (70 eV), m/z 202 (M+, 34),
187 (100), 173 (34), 160 (74), 148 (40), 144 (59), 131 (34),
115 (43), 43 (83); HRMS: Calcd for C13H14O2: 202.0994.
Found: 202.0991.
4-Methoxy-2-(1-propenyl)-1-vinyloxybenzene (5c)
1-(4-Propenyl-3-vinyloxyphenyl)-ethanone (5f)
Pure 5c (0.85 g, 89%) was obtained as liquid: Rf = 0.488
(ethyl acetate: n-hexane = 1:20), 1H-NMR (CDCl3, 400 MHz)
d 1.87 (dd, J = 6.4 Hz, 1.6 Hz, 3H, ArCH=CHCH3), 3.74 (s,
3H, OCH3), 4.26 (dd, J = 6.0 Hz, 1.6 Hz, 1H, OCH=CH2),
4.49 (dd, J = 14.0 Hz, 1.6 Hz, 1H, OCH=CH2), 6.22 (dq, J =
16.0 Hz, 6.4 Hz, 1H, ArCH=CHCH3), 6.53 (dd, J = 14.0 Hz,
6.0 Hz, 1H, OCH=CH2), 6.59 (dq, J = 16.0 Hz, 1.6 Hz, 1H,
ArCH=CHCH3), 6.68 (dd, J = 8.8 Hz, 2.8 Hz, 1H, H-5), 6.84
(d, J = 8.8 Hz, 1H, H-6), 6.97 (d, J = 2.8 Hz, 1H, H-3);
13C-NMR (CDCl3, 100 MHz) d 18.66, 55.35, 92.45, 111.02,
113.02, 119.59, 124.90, 127.36, 129.88, 146.81, 150.27,
155.93; EI-MS (70 eV), m/z 190 (M+, x2), HRMS: Calcd for
C12H14O2: 190.0988. Found: 190.0983.
Pure 5f (0.80 g, 80%) was obtained as colorless liquid,
Rf = 0.68 (EA: Hexane = 1:4), 1H-NMR (CDCl3, 200 MHz) d
1.94 (dd, J = 6.4 Hz, 1.8 Hz, 3H, ArCH=CHCH3), 2.57 (s, 3H,
ArCOCH3), 4.48 (dd, J = 6.2 Hz, 1.8 Hz, 1H, ArOCH=CH2),
4.73 (dd, J = 13.8 Hz, 1.8 Hz, 1H, ArOCH=CH2), 6.40 (dq, J
= 15.8 Hz, 6.4 Hz, 1H, ArCH=CHCH3), 6.65 (dd, J = 13.8 Hz,
6.2 Hz, 1H, ArOCH=CH2), 6.70 (dq, J = 15.8 Hz, 1.8 Hz, 1H,
ArCH=CHCH3), 7.52 (d, J = 8.0 Hz, 1H, H-5), 7.54 (d, J = 1.4
Hz, 1H, H-2), 7.62 (dd, J = 8.0 Hz, 1.4 Hz, H-6); 13C-NMR
(CDCl3, 50 MHz) d 19.08, 26.53, 95.42, 116.57, 123.76,
124.36, 126.28, 130.41, 133.33, 136.44, 148.33, 153.03,
196.86; EI-MS (70 eV), m/z 202 (M+, 43), 187 (38), 173 (29),
159 (28), 145 (97), 131 (14), 115 (24), 91 (16), 43 (100);
HRMS: Calcd for C13H14O2: 202.0994. Found: 202.0992.
4-Chloro-2-(1-propenyl)-1-vinyloxybenzene (5d)
Pure 5d (0.87 g, 89%) was obtained as liquid, Rf = 0.72
(ethyl acetate: n-hexane = 1:20), 1H-NMR (CDCl3, 400 MHz)
d 1.89 (dd, J = 6.4 Hz, 1.6 Hz, 3H, ArCH=CHCH3), 4.39 (dd,
J = 6.0 Hz, 1.6 Hz, 1H, OCH=CH2), 4.64 (dd, J = 13.8 Hz, 1.6
Hz, 1H, OCH=CH2), 6.24 (dq, J = 15.8 Hz, 6.4 Hz, 1H,
ArCH=CHCH3), 6.53 (dd, J = 13.8 Hz, 6.0 Hz, 1H, OCH=CH2),
6.58 (dq, J = 15.8 Hz, 1.6 Hz, 1H, ArCH=CHCH3), 6.73 (d, J
= 8.6 Hz, 1H, H-6), 7.10 (dd, J = 8.6 Hz, 2.4 Hz, 1H, H-5),
7.41 (d, J = 2.4 Hz, 1H, H-3); 13C-NMR (CDCl3, 100 MHz) d:
18.79, 94.65, 118.85, 123.89, 126.16, 127.34, 128.66, 128.84,
130.32, 148.79, 151.43; EI-MS (70 eV) m/z 194 (M+, 29), 165
(42), 159 (41), 131 (43), 115 (100), 103 (63), 89 (52), 77 (53),
4-tert-Butyl-2-(1-propenyl)-1-vinyloxybenzene (5g)
Pure 5g (0.98 g, 90%) was obtained as liquid, Rf = 0.76
(ethyl acetate: n-hexane = 1:20), 1H-NMR (CDCl3, 400 MHz)
d 1.30 (s, 9H, ArC(CH3)3), 1.89 (dd, J = 6.4 Hz, 1.6 Hz, 3H,
ArCH=CHCH3), 4.33 (dd, J = 6.0 Hz, 1.6 Hz, 1H, OCH=CH2),
4.62 (dd, J = 14.0 Hz, 1.6 Hz, 1H, OCH=CH2), 6.25 (dq, J =
15.8 Hz, 6.4 Hz, 1H, ArCH=CHCH3), 6.58 (dd, J = 14.0 Hz,
6.0 Hz, 1H, OCH=CH2), 6.66 (dq, J = 15.8 Hz, 1.6 Hz, 1H,
ArCH=CHCH3), 6.85 (d, J = 8.6 Hz, 1H, H-6), 7.18 (dd, J =
8.6 Hz, 2.4 Hz, 1H, H-5), 7.46 (d, J = 2.4 Hz, 1H, H-3); 13C-
NMR (CDCl3, 100 MHz) d 18.83, 31.43, 34.29, 93.58,
117.29, 123.34, 124.75, 125.51, 126.85, 127.89, 146.30,