178 JOURNAL OF CHEMICAL RESEARCH 2008
7.32 (4H, m), 7.65 (4H, m, J* = 8.9 Hz), 7.70 (4H, m, J* = 8.9 Hz),
8.09 (4H, m, J* = 8.9 Hz); dC (67.8 MHz, CDCl3) 120.5 (2C, q, 1JC-F
= –257 Hz), 121.4 (4C), 127.6 (4C), 128.8 (4C), 130.6 (4C), 132.1
(2C), 138.2 (2C), 146.1 (2C), 149.6 (2C, q, J = 1.7 Hz), 193.7 (2C,
CO); MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 531 (MH+, 9.4), 423
(5.9), 265 (100). (Found: C, 63.3; H, 3.1. C28H16F6O4 requires C,
63.40; H, 3.04).
To 11b, column chromatography on silica gel (hexane/CHCl3 4:1)
provided 1h as a deep ‘metallic' purple solid; m.p. 269°C; (Found:
M+, 861.9996. C43H24O3 requires M, 79Br81BrF6: 861.9981); nmax
(KBr/cm-1) 1704, 1488, 1263, 1211, 1165, 1072, 1007, 845, 809,
771; dH (270 MHz, CDCl3) 7.02 (4H, m, J* = 7.6 Hz), 7.14 (4H,
m, J* = 7.8 Hz), 7.27 (4H, m, J* = 7.6 Hz), 7.37–7.45 (8H, m),
7.59 (4H, m, J* = 8.4 Hz); dC (67.8 MHz, CDCl3) 118.1 (2C, q,
2J = –251 Hz), 121.3 (4C), 122.2 (2C), 124.2 (2C), 126.7 (4C), 128.3
(4C), 129.4 (2C), 129.9 (4C), 131.5 (4C), 131.6 (4C), 131.9 (2C),
138.6 (2C), 140.1 (2C), 149.0 (2C, q, J = 2.2 Hz), 199.1 (CO); MS
(FAB, 3-nitrobenzyl alcohol) m/z (%) = 864 (81Br2)M+, 25), 862
([79Br81Br]M+, 36), 860 ([79Br2]M+, 17), 498 (14).
(Z)-1,2-Dibenzoyl-1,2-bis(3,4,5-trimethoxyphenyl)ethene (Z-3c):
Slowly crystallising colourless solid; (Found: MH+, 569.2174.
C34H33O8 requires 569.2175); nmax (KBr/cm-1) 3056, 2928, 1581,
1504, 1450, 1413, 1341, 1243, 1128, 1006, 750; dH (270 MHz, CDCl3)
3.59 (12H, s, 4 OCH3), 3.79 (6H, s, 2 OCH3), 6.40 (4H, s), 7.26–7.48
(6H, m), 7.87 (4H, m, J* = 7.3 Hz); dC (67.8 MHz, CDCl3) 56.1, 60.9,
107.0, 128.4, 129.8, 130.5, 133.2, 136.4, 138.2, 144.3, 153.3, 197.4;
MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 569 (57, MH+).
(Z)-1,2-Dibenzoyl-1,2-bis(4-bromophenyl)ethene (Z-3e) (for Z-3d,
see also refs 49,50; Z-3e had been reported previously51,52): Colourless
solid; m.p. 228°C (Found: MH+, 558.9738. C29H19O279Br81Br requires
MH, 558.9734); nmax (KBr/cm-1) 2924, 1663, 1593, 1484, 1273,
1012, 829, 713; dH (270 MHz, CDCl3) 7.03 (4H, m, J* = 8.2 Hz),
7.29–7.37 (8H, m), 7.43 (2H, m), 7.80 (4H, m, J* = 8.2 Hz); dC (67.8
MHz, CDCl3) 123.1, 128.4, 130.0, 131.2, 132.2, 133.3, 133.8, 135.9,
143.8, 196.2 (C=O); MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 559
([81Br79Br]MH+, 12).
(Z)-1,2-Dibenzoyl-1,2-bis(4-methoxybiphenyl)ethene
(Z-3g):
Colourless solid; m.p. 233°C; (Found: MH+, 601.2377. C42H33O4
requires MH, 601.2379); nmax (KBr/cm-1) 3032, 2924, 1653, 1602,
1495, 1289, 1246, 1178, 1037, 826, 809; dH (270 MHz, CDCl3) 3.82
(6H, s, 2 OCH3), 6.92 (4H, m, J* = 8.9 Hz), 7.23–7.49 (18H, m),
7.88 (4H, m, J* = 7.2 Hz); dC (67.8 MHz, CDCl3) 55.4 (OCH3),
114.3 (CH), 126.7 (CH), 128.0 (CH), 128.4 (CH), 130.1 (CH), 130.3
(CH), 132.5 (Cquat), 133.0 (CH), 133.6 (Cquat), 136.5 (Cquat), 140.5
(Cquat), 144.1 (Cquat), 159.5 (Cquat), 197.1 (Cquat, C=O). MS (FAB,
3-nitrobenzyl alcohol) m/z (%) 601 (MH+, 38).
Further tetracyclones
Hexamethoxytetracyclone (1c): Red-brown needles, m.p. 175°C;
[Found: MH+ 565.2228. C35H33O7 requires (MH+), 565.2226]; nmax
(KBr/cm-1) 3070, 2996, 2926, 1712, 1579, 1411, 1351, 1240, 1128,
1004, 852; dH (270 MHz, CDCl3) 3.45 (12H, s, 4 OCH3), 3.84 (6H,
s, 2 OCH3), 6.17 (4H, s), 7.24–7.28 (10H, m); dC (67.8 MHz, CDCl3)
55.9, 61.0, 107.2, 125.3, 127.6, 128.1, 130.1, 130.8, 138.3, 152.6 (two
sets of isochronous nuclei), 153.6, 199.9; MS (FAB, 3-nitrobenzyl
alcohol) m/z (%) 565 (MH+, 36), 564 (M+, 32). (Found: C, 74.1; H,
5.7. C35H32O7 requires C, 74.45; H, 5.71).
3,4-Bis(4-trifluoromethoxybiphenyl)-2,5-diphenylcyclopenta-
dienone (1i): Deep-purple solid, m.p. 208°C; (Found: MH+ 705.1862.
C43H27O3F6 requires: MH+, 705.1864); nmax (KBr/cm-1) 1704, 1490,
1267, 1219, 1164, 1005, 920, 841, 738, 693;dH (270MHz, CDCl3)7.04
(4H, d, 3J = 8.6 Hz), 7.24–7.29 (14H, m), 7.41 (4H, m, J* = 8.6 Hz),
7.58 (4H, m, J* = 8.9 Hz); dC (67.8 MHz, CDCl3) 120.5 (q, 2C, 1JCF
= –256 Hz), 121.3 (4C), 125.8 (2C), 126.5 (4C), 127.6 (2C), 128.1
(4C), 128.3 (4C), 130.1 (4C), 130.2 (4C), 130.7 (2C), 132.4 (2C),
138.8 (2C), 139.7 (2C), 148.9 (q, J = 1.7 Hz), 153.6 (2C), 200.0
(CO); MS FAB, 3-nitrobenzyl alcohol) m/z (%) 705 (MH+, 100), 676
(9.2), 587 (11), 498 (14), 338 (40), 265 (30).
(Z)-1,2-Bis(-4-bromobenzoyl)-1,2-bis(4-trifluoromethoxybiphenyl
)ethene (Z-3h):Slowly crystallising colourless solid; (Found: MH+,
867.0005. C42H25O479Br81BrF6 requires MH, 867.0008). nmax (KBr/
cm-1) 1654, 1584, 1494, 1397, 1259, 1165, 1068, 1003, 828; dH (270
MHz, CDCl3) 7.24 (4H, m, J* = 7.0 Hz), 7.38–7.57 (16H, m), 7.72
(4H, d, J* = 8.4 Hz); MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 867
(79Br81BrMH+, 13).
(Z)-1,2-Dibenzoyl-1,2-bis(4-trifluoromethoxybiphenyl)ethene (Z-3i):
Slowly crystallising colourless solid; (Found: MH+, 709.1808.
C42H27O4F6 requires MH, 709.1814); nmax (neat/cm-1) 3028, 2926,
2866, 1655, 1611, 1510, 1453, 1251, 1173, 1089, 1034, 1004, 838,
809, 755, 671; dH (270 MHz, CDCl3) 7.22–7.47 (14H, m), 7.35 (4H,
m, J* = 7.8 Hz), 7.53 (4H, m, J* = 8.6 Hz), 7.88 (4H, m, J* = 7.6 Hz);
1
dC (67.8 MHz, CDCl3) 120.5 (2C, JCF -256 Hz), 121.2 (4C), 127.3
2,5-Bis(biphenyl)-3,4-diphenylcyclopentadienone (1k):47 Brown-
black solid; m.p. 282°C; nmax (KBr/cm-1) 1709, 1485, 1301, 1115,
1084, 1026, 1006, 915, 850, 798, 761, 738, 708 cm-1; dH (270 MHz,
CDCl3) 6.98 (4H, m, J* = 8.4 Hz), 7.17–7.35 (12H, m), 7.41 (4H,
m), 7.49 (4H, m, J* = 8.1 Hz), 7.58 (4H, m, J* = 7.8 Hz); dC (67.8
MHz, CDCl3) 124.9 (2C), 126.7 (4C), 127.0 (4C), 127.3 (2C), 128.1
(4C), 128.6 (2C), 128.7 (4C), 129.3 (4C), 129.7 (2C), 130.5 (4C),
133.2 (2C), 140.0 (2C), 140.7 (2C), 154.6 (2C), 200.5; MS (FAB, 3-
nitrobenzyl alcohol) m/z (%) 536 (M+, 0.5).
2,5-Bis(biphenyl)-3,4-bis(4-fluorophenyl)cyclopentadienone
(1l): Brown-black solid; 235°C; (Found: M+ 572.1941. C41H26OF2
requires: 572.1952); nmax (KBr/cm-1) 1702, 1540, 1531, 1529, 1507,
1223, 1158, 1122, 1006, 859, 843, 755, 700, 585, 569, 536, 516, 496;
dH (270 MHz, CDCl3) 6.89–6.96 (8H, m), 7.24–7.60 (18H, m); dC
(67.8 MHz, CDCl3) 115.5 (4C, d, JCF = 20.7 Hz), 125.2 (2C), 126.8
(4C), 127.0 (4C), 127.5 (2C), 128.8 (4C), 128.9 (2C), 129.4 (2C),
130.4 (4C), 131.3 (4C, d, JCF = 11 Hz), 140.3 (2C), 140.5 (2C), 153.1
(2C), 164.0 (2C, d, JCF = –232 Hz), 200.1; MS (FAB, 3-nitrobenzyl
alcohol) m/z (%) 572 (M+, 1.1).
(4C), 128.3 (4C), 128.4 (4C), 130.1 (4C), 130.4 (4C), 133.1 (2C),
134.6 (2C), 136.3 (2C), 138.7 (2C), 139.6 (2C), 144.1 (2C), 148.9
(q, 2C, J 1.7 Hz), 196.7 (2C, CO); MS (FAB, 3-nitrobenzyl alcohol)
m/z (%) 709 (MH+, 24), 265 (29), 105 (100).
(Z)-1,2-Bis(biphenylcarbonyl-1,2-bis(phenyl)ethene
(Z-3k):
Colourless needles; m.p. 234°C; (Found: MH+, 541.2159. C40H29O2
requires MH+, 541.2168); nmax (neat/cm-1) 1663, 1603, 1486, 1442,
1404, 1263, 1178, 1072, 1029, 1004, 849, 768, 728, 695, 579;
dH (270 MHz, CDCl3) 7.22 (10H, m), 7.33–7.43 (6H, m), 7.52–
7.60 (8H, m), 7.93 (4H, m, J* = 8.4 Hz); dC (67.8 MHz, CDCl3)
127.02 (4C), 127.26 (4C), 128.10 (2C), 128.41 (2C), 128.71 (4C),
128.83 (4C), 129.85 (4C), 130.63 (4C), 135.17 (2C), 135.31 (2C),
139.99 (2C), 144.48 (2C), 145.66 (2C), 196.48 (2C, CO); MS (FAB,
3-nitrobenzyl alcohol) m/z (%) 541 (MH+, 4.6). (Found: C, 88.9; H,
5.15. C40H28O2 requires C, 88.86; H, 5.22).
(Z)-1,2-Bis(biphenylcarbonyl-1,2-bis(4-fluorophenyl)ethene
(Z-3l): Colourless needles; m.p. 227°C; (Found: MH+, 577.1984.
C40H27O2F2 requires 577.1979); nmax (neat/cm-1) 1651, 1599, 1504,
1404, 1236, 1006, 847, 818, 760, 690; dH (270 MHz, CDCl3) 6.90–
6.96 (4H, m), 7.17–7.44 (10H, m), 7.52–7.60 (8H, m), 7.89 (4H, m,
J* = 7.8 Hz); dC 116.1 (4C, JCF 21.2 Hz), 127.1 (4C), 127.3 (4C),
128.2 (2C), 128.9 (4C), 130.6 (4C), 131.2 (2C, d, JCF 3.4 Hz), 131.7
(4C, d, JCF 7.9 Hz), 134.9 (2C), 139.9 (2C), 143.6 (2C), 145.9 (2C),
162.6 (2C, d, JCF -250 Hz), 196.1 (2C, CO); MS (FAB, 3-nitrobenzyl
alcohol) m/z (%) 577 (MH+, 8.5).
Thermal reaction of tetracyclone (1a) with oxygen: Tetracyclone
(1a) (450 mg, 1.17 mmol) in diphenylether (2.0 ml) was heated at
135°C for 36 h. Thereafter, the solution was subjected directly to
column chromatography on silica gel with hexane as an initial eluant
(to separate off diphenyl ether), thereafter with a solvent mixture of
hexane/CHCl3/ether (10:1:1) to give Z-3a (124 mg, 27%) and 4a
(112 mg, 24%).
4,5-Bis-(4-methoxyphenyl)-3,6-diphenyl-a-pyrone
(4b):18
Colourless solid; m.p. 246°C (Lit18 234°C; 1H NMR (270 MHz, CDCl3)
d 3.66 (3H, s, OCH3), 3.72 (3H, s, OCH3), 6.49 (2H, m, J* = 8.6 Hz),
6.61 (2H, m, J* = 8.6 Hz), 6.63 (2H, m, J* = 8.6 Hz), 6.75 (2H, m,
J* = 8.6 Hz), 7.11–7.34 (10H, m).
Selected spectroscopic and analytical data of (Z)-1,2-diaroyl-1,2-
diarylethenes 3 and a-pyrones 4
(Z)-1,2-Dibenzoyl-1,2-bis(4-methoxyphenyl)ethene (Z-3b): Pale
yellow needles; m.p. 189°C; (Found: MH+ 449.1756. C30H25O4
requires: MH+, 449.1753); nmax (KBr/cm-1) 3058, 2926, 1657, 1605,
1509, 1250, 1175, 1031, 835, 692; dH (270 MHz, CDCl3) 3.74 (6H, s,
2 OCH3), 6.71 (4H, m, J* = 8.6 Hz), 7.08 (4H, m, J* = 8.6 Hz), 7.41
(2H, m), 7.28 (4H, m), 7.83 (4H, m, J* = 7.3 Hz); dC (67.8 MHz,
CDCl3) 55.1, 114.1, 127.7, 128.2, 130.0, 131.3, 132.7, 136.6, 143.5,
159.4, 197.4; MS (FAB, 3-nitrobenzyl alcohol) m/z (%) 449 (MH+,
100). (Found: C, 80.5; H, 5.4. C30H24O requires C, 80.33; H, 5.39).
4,5-Bis-(4-methylphenyl)-3,6-diphenyl-a-pyrone(4d):18 Colourless
solid; m.p. 198°C; [HRMS Found: 429.1852. Calcd. for C31H25O2:
429.1855 (MH+, FAB)]; 1H NMR (270 MHz, CDCl3) d 2.13 (3H,
s, CH3), 2.21 (3H, s, CH3), 6.59 (2H, m, J* = 8.1 Hz), 6.72 (2H, m,
J* = 8.1 Hz), 6.74 (2H, m, J* = 8.1 Hz), 6.85 (2H, m, J* = 8.1 Hz),
7.10–7.33 (10H, m); 13C NMR (67.8 MHz, CDCl3) d 21.1 (CH3), 21.1
(CH3), 119.7 (Cquat), 124.9 (Cquat), 127.1 (CH), 127.6 (2C, CH), 127.8
(2C, CH), 128.0 (2C, CH), 128.8 (2C, CH), 129.2 (CH), 129.3 (4C,
PAPER: 08/5162