C. Kuang et al. / Tetrahedron 61 (2005) 637–642
641
for 0.5–3.0 min. The reaction mixture was then removed
from the oven and cooled to room temperature. Water and
ether were added to the reaction mixture and the organic
layer was separated. Aqueous layer was extracted with
ether. The combined organic layers were washed with water
and brine, and dried over anhydrous magnesium sulfate.
Evaporation of the solvent gave the crude product, which
was subjected to column chromatography (silica gel,
hexane–ether) to afford (E)-b-arylvinyl bromides 2.
102 (70); HRMS calcd for C8H769Br81Br. m/z 261.8816.
Found m/z 261.8825.
4.2.8. (E)-b-Bromo-4-chlorostyrene (2h).3d,17 The crude
product was purified by silica gel column chromatography
eluted with 10% ether in hexane; mp 47–48 8C (MeOH)
(lit.17 47–48 8C); IR (nujol) 1604, 1586, 945 cmK1 1H
;
NMR (CDCl3) d 6.75 (1H, d, JZ13.9 Hz), 7.05 (1H, d, JZ
13.9 Hz), 7.21 (2H, d, JZ8.6 Hz), 7.29 (2H, d, JZ8.6 Hz).
4.2.1. (E)-b-Bromostyrene (2a).3d,11 Column chromato-
graphy was carried out with hexane as an eluent; colorless
4.2.9. (E)-b-Bromo-2-chlorostyrene (2i).3i The crude
product was purified by silica gel column chromatography
eluted with 20% ether in hexane; colorless oil; IR (neat)
1605, 1470, 1440, 945 cmK1; 1H NMR (CDCl3) d 6.80 (1H,
d, JZ13.9 Hz), 7.21–7.25 (2H, m), 7.3–7.4 (2H, m), 7.47
(1H, d, JZ13.9 Hz).
1
oil; IR (neat) 1609, 1575, 941 cmK1; H NMR (CDCl3) d
6.77 (1H, d, JZ13.9 Hz), 7.11 (1H, d, JZ13.9 Hz), 7.27–
7.32 (5H, m).
4.2.2. (E)-b-Bromo-4-methylstyrene (2b).3d,11 Column
chromatography was carried out with hexane as an eluent;
mp 46.0–46.5 8C (EtOH) (lit.6g 46.0–46.5 8C); IR (nujol)
4.2.10. (E)-b-Bromo-4-fluorostyrene (2j).16 The crude
product was purified by silica gel column chromatography
eluted with 5% ether in hexane; colorless oil; IR (neat)
1602, 1589, 946 cmK1; 1H NMR (CDCl3) d 6.67 (1H, d, JZ
13.9 Hz), 6.95–7.03 (2H, m), 7.04 (1H, d, JZ13.9 Hz),
7.21–7.25 (2H, m); 13C NMR (CDCl3) d 106.07 (d, JZ
2.5 Hz), 115.76 (d, JZ20.7 Hz), 127.68 (d, JZ8.5 Hz),
132.10 (d, JZ3.7 Hz), 135.93, 162.56 (d, JZ247.8 Hz);
EIMS m/z 202 ((MC2)%C, 28), 200 (MC, 27), 202 (28), 149
(100); HRMS calcd for C8H769BrF. m/z 199.9637. Found m/z
199.9629.
1
1605, 1511, 931 cmK1; H NMR (CDCl3) d 2.32 (3H, s),
6.70 (1H, d, JZ13.9 Hz), 7.06 (1H, d, JZ13.9 Hz), 7.12
(2H, d, JZ8.3 Hz), 7.19 (2H, d, JZ8.3 Hz).
4.2.3. (E)-b-Bromo-4-methoxystyrene (2c).3d,12 Column
chromatography was carried out with 10% ether in hexane
as an eluent; mp 58–59 8C (EtOH) (lit.12 58–59 8C); IR
1
(nujol) 1607, 1513, 950 cmK1; H NMR (CDCl3) d 3.81
(3H, s), 6.61 (1H, d, JZ13.9 Hz), 6.85 (2H, d, JZ8.9 Hz),
7.04 (1H, d, JZ13.9 Hz), 7.23 (2H, d, JZ8.9 Hz).
4.2.11. (E)-b-Bromo-3-fluorostyrene (2k).16 The crude
product was purified by silica gel column chromatography
eluted with 5% ether in hexane; colorless oil; IR (neat)
1611, 1582, 937 cmK1; 1H NMR (CDCl3) d 6.77 (1H, d, JZ
13.9 Hz), 6.93–7.06 (4H, m), 7.10–7.30 (1H, m); 13C NMR
(CDCl3) d 108.03, 112.64 (d, JZ23.2 Hz), 115.11 (d, JZ
22.0 Hz), 167.45 (d, JZ2.5 Hz), 130.26 (d, JZ8.5 Hz),
136.06 (d, JZ2.4 Hz), 137.96 (d, JZ7.3 Hz), 162.98 (d, JZ
246.6 Hz); EIMS m/z 202 ((MC2)%C, 28), 200 (MC, 27),
202 (28), 149 (100); HRMS calcd for C8H769BrF. m/z
199.9637. Found m/z 199.9642.
4.2.4. (E)-b-Bromo-3,4-methylenedioxystyrene (2d).3h
Column chromatography was carried out with 10% ether
in hexane as an eluent; mp 52.5–53.0 8C (hexane); IR
1
(nujol) 1505, 1250, 935 cmK1; H NMR (CDCl3) d 5.96
(2H, s), 6.59 (1H, d, JZ13.7 Hz), 6.77 (2H, m), 6.81 (1H, s),
6.99 (1H, d, JZ13.7 Hz); 13C NMR (CDCl3) d 101.27,
104.51, 105.39, 108.44, 120.93, 130.27, 136.67, 147.76,
148.13; EIMS m/z 228 ((MC2)%C, 38), 226 (MC, 40), 175
(100); HRMS calcd for C9H779Br O2. m/z 225.9629. Found
m/z 225.9635.
4.2.5. (E)-1-(b-Bromovinyl)naphthalene (2e).13 The crude
product was purified by silica gel column chromatography
eluted with 5% ether in hexane; colorless oil; IR (neat)
1603, 1590, 935 cmK1; 1H NMR (CDCl3) d 6.76 (1H, d, JZ
13.9 Hz), 7.38–7.56 (4H, m), 7.79–7.86 (3H, m), 8.02 (1H,
d, JZ8.9 Hz).
4.2.12. (E)-4-(b-Bromovinyl)benzoic acid methyl ester
(2l).16 The crude product was purified by silica gel column
chromatography eluted with 25% ether in hexane; mp 60–
61 8C (hexane); IR (nujol) 1732, 1607, 1584, 936 cmK1; 1H
NMR (CDCl3) d 3.92 (3H, s), 6.92 (1H, d, JZ14.0 Hz), 7.13
(1H, d, JZ14.0 Hz), 7.36 (2H, d, JZ8.3 Hz), 7.98 (2H, d,
JZ8.3 Hz); 13C NMR (CDCl3) d 52.17, 109.38, 125.95,
129.63, 130.10, 136.32, 140.05, 166.61; EIMS m/z 242
((MC2)%C, 100), 240 (MC, 100), 211 (100), 181 (75), 102
(70); HRMS calcd for C10H891BrO2. m/z 241.9765. Found
m/z 241.9774.
4.2.6. (E)-2-(b-Bromovinyl)naphthalene (2f).14 The crude
product was purified by silica gel column chromatography
eluted with 5% ether in hexane; mp 84–85 8C (EtOH); IR
1
(nujol) 1611, 1594, 945 cmK1; H NMR (CDCl3) d 6.90
(1H, d, JZ13.9 Hz), 7.26 (1H, d, JZ13.9 Hz), 7.44–7.49
(3H, m), 7.69 (1H, d, JZ1.0 Hz), 7.77–7.83 (3H, m).
4.2.13. 4-(3-Bromo-4-oxo-oxetan-2-yl)-benzoic acid
methyl ester (3). The crude product was purified by silica
gel column chromatography eluted with 50% ether in
hexane; Yield: 20%; mp 85–86 8C (hexane/etherZ6/4); IR
(nujol) 1850 (g CO), 1725 cmK1; 1H NMR (CDCl3) d 3.95
(3H, s), 4.99 (1H, d, JZ3.96 Hz), 5.64 (1H, d, JZ3.96 Hz),
7.50 (2H, d, JZ8.4 Hz), 8.12 (2H, d, JZ8.4 Hz); 13C NMR
(CDCl3) d 46.72, 52.45, 80.29, 125.31, 130.45, 131.68,
139.20, 163.57, 166.15; EIMS m/z 286 ((MC2)%C, 47), 284
(MC, 46), 255 (25), 240 (MCKCO2, 46), 209 (80), 122
4.2.7. (E)-b-Bromo-4-bromostyrene (2g).15,16 The crude
product was purified by silica gel column chromatography
eluted with 10% ether in hexane; mp 67–68 8C (lit.15 67–
68 8C); IR (nujol) 1610, 1589, 930 cmK1; 1H NMR (CDCl3)
d 6.78 (1H, d, JZ14.2 Hz), 7.04 (1H, d, JZ14.2 Hz), 7.15
(2H, d, JZ8.3 Hz), 7.44 (2H, d, JZ8.3 Hz); 13C NMR
(CDCl3) d 107.33, 122.17, 127.55, 131.93, 134.77, 136.03;
EIMS m/z 264 ((MC2)%C, 90), 262 (MC, 100), 181 (78),