P. Babin, B. Bennetau / Tetrahedron Letters 42 (2001) 5231–5233
5233
3
4
3
129.6 (CH), 137.0 and 137.1 (CH), 149.1 (C), 155.6 and
155.9 (C), 157.4 and 157.5 (CO). Some peaks are split into
two due to the presence of Z/E isomers. Compound 3 was
purified by distillation: oil (33%); bp 103–104°C/0.5 Torr;
IR (KBr): 1774, 1681, 1617, 1606. 1H NMR (250 MHz,
CDCl3): 5.0 (m, 1H), 5.1–5.2 (m, 2H), 6.55 (m, 1H), 7.05
(m, 1H), 7.18 (m, 1H), 7.61 (m, 1H), 7.91 (m, 1H). 13C
NMR (50.3 MHz, CDCl3): 91.9 and 92.2 (CH), 112.2 (C),
115.0 and 115.2 (CH2), 118.7 and 118.8 (CH), 123.9 and
124.1 (CH), 127.7 and 127.8 (CH), 129.7 (CH), 137.4
(CH), 150.1 and 150.2 (C), 156.7 and 156.8 (C), 157.5 and
157.6 (CO). Some peaks are split into two due to the
presence of Z/E isomers. 4 was purified by distillation: oil
(46%); bp 108–109°C/0.5 Torr; IR (KBr): 1771, 1731,
1614, 1591. 1H NMR (250 MHz, CDCl3): 3.51 and 3.53
(2s, 3H), 5.7 and 5.72 (2s, 1H), 6.86–7.08 (m, 2H), 7.46 (m,
1H), 7.77 (dd, 1H, 3J=7.8 Hz, 4J=1.7 Hz). 13C NMR
(50.3 MHz, CDCl3): 60.8 and 60.9 (CH3), 115.8 and 115.9
(C), 119.0 and 119.1 (CH), 123.7 and 124.2 (CH), 128.8
(CH), 130.0 and 130.1 (CH), 136.9 and 137.6 (CH), 142.6
and 142.8 (C), 156.1 (C), 157.4 (CO). Some peaks are split
into two due to the presence of Z/E isomers. Compounds
5a–b were purified by chromatography (SiO2, pentane/
dichloromethane 1:1): solid (27%). Compound 5a: mp
93°C; IR (KBr): 1771, 1681, 1609, 1593. 1H NMR (250
MHz, CDCl3): 2.46 (s, 3H), 5.57 (s, 1H), 7.08–7.38 (m,
3J=7.6 Hz, J=7.8 Hz, J=1.7 Hz), 8.04 (dd, 1H, J=7.8
Hz, 4J=1.6 Hz). 13C NMR (50.3 MHz, CDCl3): 21.2
(CH3), 91.3 (CH), 111.2 (C), 115.8 (CH), 123.8 (CH),
125.2 (CH), 127.4 (CH), 128.5 (CH), 128.9 (CH), 129.8
(CH), 132.3 (C), 135.5 (CH), 138.1–149.4–155.9 (3C),
156.4 (CO). Compound 5b: mp 102°C; IR (KBr): 1758,
1677, 1613, 1593. 1H NMR (250 MHz, CDCl3): 2.41 (s,
3
3H), 5.49 (s, 1H), 7.08 (d, 1H, J=8.0 Hz), 7.14–7.38 (m,
3
3
4H), 7.47 (d, 1H, J=7.9 Hz), 7.67 (ddd, 1H, J=7.6 Hz,
4
3
4
3J=7.8 Hz, J=1.7 Hz), 8.01 (dd, 1H, J=7.8 Hz, J=1.6
Hz). 13C NMR (50.3 MHz, CDCl3): 21.5 (CH3), 91.7
(CH), 112.6–115.9–124.2–125.0–127.3–128.4–128.9–129.9
(8CH), 133.1 (C), 137.3 (CH), 138.3–149.9–156.2 (3C),
156.7 (CO). 6 was purified by distillation: solid (58%); bp
130–131°C/0.5 Torr; mp 30°C; IR (KBr): 1769, 1710, 1612,
1
1591. H NMR (250 MHz, CDCl3): 1.50 (s, 6H), 2.22 (s,
3
4
4H), 7.01 (dd, 1H, J=8.3 Hz, J=0.6 Hz), 7.10 (ddd, 1H,
3J=7.7 Hz, 3J=7.8 Hz, 4J=0.6 Hz), 7.54 (ddd, 1H,
3
4
3
3J=8.3 Hz, J=7.7 Hz, J=1.7 Hz), 7.88 (dd, 1H, J=7.8
Hz, 4J=1.7 Hz). 13C NMR (50.3 MHz, CDCl3): 25.3–
25.6–28.3–28.7–28.8 (5CH2), 102.5–102.3 (2C), 115.6–
123.2–129.8–136.8 (4CH), 141.7–156.7 (2C), 158.8 (CO).
5. Babin, P.; Bennetau B.; Dunogue`s, J. Rhodia Chimie,
1999, FR99/04656; 2000 WOFR0000974.
6. Ankersen, M.; Senning, A. Acta Chem. Scand. 1989, 43,
793.
7. Falborg, L.; Senning, A. Acta Chem. Scand. 1993, 47, 514.
3
4H), 7.44 (s, 1H), 7.55 (d, 1H, J=7.8 Hz), 7.77 (ddd, 1H,
.