PAPER
11,12-Didehydrodibenzo[a,e]cycloocten-5(6H)-one
2551
13C NMR (75 MHz, CD2Cl2): d = –5.0, –4.5 [q, Si(CH3)2-t-Bu],
18.4 [s, C(CH3)3], 26.0 [q, C(CH3)3], 50.6 (t, C-6), 76.1 (d, C-5),
111.0, 113.1 (s, Calkyne), 121.3, 124.3 (s, Cq), 125.2, 126.1, 126.3,
126.9, 127.1, 128.1, 128.2, 130.3 (d, Carom), 152.2, 156.8 (s, Cq).
HRMS–FAB: m/z [M]+ calcd for C22H26OSi: 334.1753; found:
334.1751.
Anal. Calcd for C16H10O: C, 88.05; H, 4.62. Found: C, 87.85; H,
4.66.
{(h5-Cyclopentadienyl)}{h4-10,20(19)-dihydrotetraben-
zo[c,c',g,g']cyclobuta[1,2-a:3,4-a']dicyclooctene-9,19(20)-di-
one}cobalt(I) (Isomeric Mixture) (20)
A soln of ynone 10 (1.2 g, 5.6 mmol) in decalin (40 mL) was added
dropwise over 3 days to a soln of CpCo(CO)2 (0.5 g, 2.8 mmol) in
decalin (210 mL) at 177 °C. The solvent was then removed under
vacuum, and the red-brown residue was purified by column chro-
matography [silica gel, hexane–CH2Cl2 (1:1)] to give a red solid;
yield: 438 mg (28%); mp 191 °C; Rf = 0.12 (hexane–CH2Cl2, 1:1).
UV/Vis (CH2Cl2): λmax (log ε): 258 (3.75), 276 (4.13), 290 (4.28),
306 nm (4.27).
Anal. Calcd for C22H26OSi: C, 79.00; H, 7.83. Found: C, 78.75; H,
7.84.
11,12-Didehydro-5,6-dihydrodibenzo[a,e]cycloocten-5-ol (19)
Bu4NF·3H2O (18 g, 56 mmol) was added to a soln of 18 (10 g, 28
mmol) in THF (250 mL) at r.t., and the mixture was then stirred for
1 h. The solvent was evaporated, and the residue was dissolved in
CH2Cl2 (200 mL) and H2O (200 mL). The aqueous layer was ex-
tracted with CH2Cl2 (3 × 75 mL), and the organic layers were com-
bined, dried (MgSO4) and concentrated to give a residue that was
purified by column chromatography (silica gel, CH2Cl2) as color-
less crystals; yield: 5 g (81%); mp 135–136 °C; Rf = 0.38 (CH2Cl2).
IR (KBr): 3440 (b), 3060 (w), 2925 (m), 2853 (w), 1665 (s), 1593
(w), 1477 (m), 1456 (w), 1287 (m), 1240 (w), 1009 (w) cm–1.
1H NMR (300 MHz, CD2Cl2): d = 4.38–4.44, 4.83–4.87 [m, 4 H,
CH2 (isomers a + b)], 4.68, 4.78 [s, 5 H, HCp, (isomers a + b)], 7.11–
8.00 [m, 16 H, Harom (isomers a + b)].
13C NMR (75 MHz, CD2Cl2): d = 48.4, 49.4 [t, CH2 (isomers a +
b)], 75.5, 76.1, 77.4, 78.4 [s, CCbd (isomers a + b)], 84.4, 84.6 [d, CCp
(isomers a + b)], 126.7, 126.8, 127.3, 128.2, 128.5, 129.3, 130.4,
130.7, 131.1, 131.3, 131.3, 131.5, 131.8, 133.3 [d, Carom (isomers a
+ b)], 133.9, 134.1, 134.4, 134.4, 135.4, 135.8, 137.3 [s, Carom (iso-
mers a + b)], 198.3, 199.2 [s, CO (isomers a + b)].
IR (KBr): 3061 (w), 3033 (w), 1602 (m), 1563 (m), 1475 (m), 1244
(w), 1203 (w), 1108 (m), 1044 (s) cm–1.
1H NMR (300 MHz, CD2Cl2): d = 2.45 (s, 1 H, OH), 2.88 (dd,
2J = 14.7 Hz, 3J = 3.6 Hz, 1 H, H-6), 3.09 (dd, 2J = 14.7 Hz, 3J = 1.9
Hz, 1 H, H-6), 4.56–4.59 (m, 1 H, H-5), 7.28–7.43 (m, 7 H, Harom),
7.71–7.74 (m, 1 H, Harom).
HRMS–FAB: m/z [M]+ calcd for C37H25O2Co: 560.1186; found:
560.1204.
UV/Vis (CH2Cl2): λmax (log ε): 268 (4.47), 296 (4.40), 340 nm
(4.13).
13C NMR (75 MHz, CD2Cl2): d = 49.1 (t, C-6), 75.4 (d, C-5), 111.9,
113.1 (s, Calkyne), 121.4, 124.3 (s, Cq), 124.1, 126.3, 127.0, 127.2,
128.3, 128.3, 129.9 (d, Carom), 152.1, 156.1 (s, Cq).
{(h5-Pentamethylcyclopentadienyl)}{h4-10,20(19)-dihydrotet-
rabenzo[c,c',g,g']cyclobuta[1,2-a:3,4-a']dicyclooctene-9,19(20)-
dione}cobalt(I) (Isomeric Mixture) (21)
HRMS–FAB: m/z [M]+ calcd for C16H12O: 220.0888; found:
To a soln of Cp*Co(CO)2 (0.8 g, 3.1 mmol) in decalin (210 mL) was
added dropwise over 3 days to a soln of ynone 10 (1.4 g, 6.2 mmol)
in decalin (40 mL) at 177 °C. The solvent was removed under vac-
uum and the red-brown residue was purified by column chromatog-
raphy [silica gel, hexane–CH2Cl2 (1:1)] to give a red solid; yield:
120 mg (6%); mp 248 °C; Rf = 0.1 (hexane–CH2Cl2, 1:1).
220.0863.
UV/Vis (CH2Cl2): λmax (log ε): 258 (3.81), 276 (4.24), 290 (4.41),
306 nm (4.41).
Anal. Calcd for C16H12O: C, 87.25; H, 5.49. Found: C, 87.43; H, 5.4.
11,12-Didehydrodibenzo[a,e]cycloocten-5(6H)-one (10)
IR (KBr): 3438 (b), 3006 (w), 2905 (w), 1662 (vs), 1593 (m), 1476
(m), 1455 (s), 1285 (m), 1237 (w), 1010 (m) cm–1.
1H NMR (300 MHz, CD2Cl2): d = 1.28, 1.29 [s, 15 H, CH3 (isomers
a + b)], 3.56–3.60, 4.31–4.63, 6.00–6.02 [m, 4 H, CH2 (isomers a +
b)], 7.14–8.04 [m, 16 H, Harom (isomers a + b)].
13C NMR (75 MHz, CD2Cl2): d = 9.05, 9.27 [q, CH3 (isomers a +
b)], 47.3, 47.3 [t, CH2 (isomers a + b)], 68.0, 74.0, 77.3, 78.5 [s, CCbd
(isomers a + b)], 91.8, 91.8 [s, CCp (isomers a + b)], 125.2, 125.3,
125.7, 126.1, 126.5, 126.6, 127.0, 127.3, 127.5, 129.5, 130.5, 130.7,
131.5, 131.7, 132.0, 132.3 [d, Carom (isomers a + b)], 133.5, 134.5,
134.9, 135.7, 136.1, 136.3, 136.6, 137.1, 137.5 [s, Carom (isomers a
+ b)], 199.9, 201.1, 201.3 [s, CO (isomers a + b)].
A soln of DMSO (1.3 mL, 18 mmol) in CH2Cl2 (20 mL) was added
dropwise to a stirred soln of oxalyl chloride (0.8 mL, 9 mmol) in
CH2Cl2 (20 mL) at –78 °C under argon. The soln was stirred at –78 °C
for 0.5 h and then a soln of ynol 19 (1.8 g, 8.2 mmol) in CH2Cl2 (80
mL) was added to the mixture. The soln was stirred at –78 °C for 20
min, Et3N (5.7 mL, 41 mmol) was added, and the mixture was
stirred at r.t. for 0.5 h. The mixture was diluted with CH2Cl2 and
washed with H2O. The aqueous layer was extracted with CH2Cl2
(3 × 75 mL), and the organic layers were combined and dried
(MgSO4). Removal of solvent and purification by column chroma-
tography (silica gel, CH2Cl2) gave yellow crystals; yield: 1.4 g
(76%); mp 83 °C; Rf = 0.66 (CH2Cl2).
IR (KBr): 3435 (br), 3060 (w), 2923 (w), 2120 (w), 1683 (vs), 1638
(m), 1595 (m), 1476 (w), 1299 (m), 1219 (w), 1164 (w), 1036 (w)
cm–1.
HRMS–MALDI: m/z [M]+ calcd for C42H35O2Co: 630.19636;
found: 630.19670.
UV/Vis (CH2Cl2): λmax (log ε): 269 (4.45), 322 (4.40), 374 (4.18),
462 (3.63) nm.
1H NMR (300 MHz, CD2Cl2): d = 3.64 (d, 2J = 11.0 Hz, 1 H, H-6),
4.16 (d, 2J = 11.0 Hz, 1 H, H-6), 7.32–7.54 (m, 8 H, Harom).
13C NMR (75 MHz, CD2Cl2): d = 49.3 (t, C-6), 109.5, 111.0 (s,
Calkyne), 122.1, 123.8 (s, Cq), 126.1, 126.4, 127.7, 127.9, 128.4,
Acknowledgment
129.4, 131.2 (d, Carom), 148.7, 155.1 (s, Cq), 200.4 (s, CO).
HRMS–FAB: m/z [M]+ calcd for C16H10O: 218.0732; found:
218.0757.
Financial support from the Deutsche Forschungsgemeinschaft is
gratefully acknowledged. S.C.K. thanks the Graduate College 850
for a fellowship.
UV/Vis (CH2Cl2): λmax (log ε): 252 (4.16), 282 (3.94), 296 (4.06),
320 nm (3.69).
Synthesis 2009, No. 15, 2547–2552 © Thieme Stuttgart · New York