F. Burgos O et al. / Tetrahedron Letters 48 (2007) 8331–8333
8333
3.1. Preparation of tricycle[5.2.1.02,6]dec-3-ene (8,9-
dihydrodicyclopentadiene)
pentadiene was prepared for the first time and fully
characterized by NMR spectroscopy. The assignments
of dicyclopentadiene were done in an attempt to charac-
terize this new brominated compound. This new pre-
parative synthesis is more easy and direct than the
route reported by Katz.
Nickel acetate (1.5 g, 6.0 mmol) and NaBH4 (6.0 mL,
6.0 mmol, 1.0 M in ethanol) were added in a hydrogena-
tion bottle and were left stable until the evolution of
hydrogen was ceased. Then, dicyclopentadiene (30.0 g,
227 mmol in 50.0 mL of ethanol) was added. The flask
was connected to a Parr hydrogenator apparatus and
purged with hydrogen three times. The Parr apparatus
was filled with hydrogen until 40 psi of pressure and
the mixture was stirred until 10% of hydrogen in excess
was consumed. The mixture was filtered over Celite and
was then cooled and filtered to separate a white solid.
This procedure was repeated three times. Yield 66–75 g
Acknowledgements
The authors thank FONDECYT for support of this
research under Grants 1020525 and 1020314 and F.B.
thanks CONICYT for Support Scholarship in Ph.D.
thesis.
1
(77% at average). H NMR (CDCl3, 200 MHz) d ppm:
1.23–1.24 (m, CH2(8,9), 4H), 1.44 (q, CH2(10), 2H),
2.12 (s, CH, 1H), 2.19–2.29 (m, H(5,7,1) 3H), 2.53 (m,
H(6) 1H), 2.99 (m, H(2), 1H), 5.60 (m, CH(3,4), 2H).
13C NMR (CDCl3, 50 MHz) d ppm: 22.39 and 25.63
(CH2(8,9)), 32.64 (CH2(5)), 39.95 and 41.37 (CH(7,1)),
41.55 (CH2(10)), 41.96 (CH(6)), 53.34 (CH(2)), 130.75
and 133.31 (CH(3,4)).
References and notes
1. (a) Mcleverty, J. A.; Ward, M. D. Acc. Chem. Res. 1998, 31,
842; (b) Ward, M. D. Chem. Soc. Rev. 1995, 24, 121; (c)
Barlow, S.; O’Hare, D. Chem. Rev. 1997, 97, 637; (d)
Ceccon, A.; Santi, S.; Orian, L.; Bisello, A. Coord. Chem.
Rev. 2004, 248, 683.
2. (a) Chang, I.-J.; Nocera, D. G. Inorg. Chem. 1989, 24, 4309;
(b) Dulebohn, J. I.; Ward, D. L.; Nocera, D. J. Am. Chem.
Soc. 1988, 110, 4054; (c) DeLaet, D. L.; Powell, D. R.;
Kubiak, C. P. Organometallics 1985, 4, 954; (d) Amshumali,
3.2. Preparation of 5-bromotricyclo[5.2.1.02,6]dec-3-ene
(5-bromo-8,9-dihydrodicyclopentadiene)
´
´
M. K.; Chavez, I.; Arancibia, V.; Burgos, F.; Manrıquez, J.
8,9-Dihydrodicyclopentadiene (5.0 g, 37.3 mmol) and
NBS (6.6 g, 37.1 mmol) were dissolved in CCl4
(30 mL) and added to a round-bottom flask fitted with
a refrigerant, a stirrer and inert atmosphere, this system
was refluxed for 4 h. At the end, the solid formed was
filtered and the solvent was evaporated. The resulting
liquid was passed through a column with silica gel using
chloroform as an eluent. An oily yellow liquid was sep-
arated. Yield 5.3 g (d = 1.32 g/ml, 67%). 1H NMR
(CDCl3, 200 MHz) d ppm: 1.00–1.15 (m, H(8,9) 4H),
1.16–1.60 (m, H(10) 2H), 2.3 (s wide, H(5,7,1) 3H),
2.96 (m, H(6), 1H), 3.22 (m, H(2), 1 H), 5.90 (s,
H(3,4), 2H). 13C NMR (CDCl3, 50 MHz) d ppm:
22.33 and 25.14 (CH2(8,9)); 39.48 and 40.10 (CH(7,1)),
40.14 (CH(6)), 41.18 (CH(10)), 51.79 (CH(2)) 58.13
(CH(5)); 133.16 and 139.29 (CH(3,4)).
M.; Molins, E.; Roig, A. J. Organomet. Chem. 2005, 690,
´
´
1340; (e) Alfonso, G.; Chavez, I.; Arancibia, V.; Manrı-
quez, J. M.; Garland, M. T.; Roig, A.; Molins, V.; Baggio,
´
R. F. J. Organomet. Chem. 2001, 620, 32; (f) Manrıquez, J.
M.; Ward, M. D.; Reiff, W.; Calabrese, J. C.; Jones, N. L.;
Carrol, P. J.; Bunel, E.; Miller, J. S. J. Am. Chem. Soc.
1995, 117, 6182; (g) Creutz, C.; Taube, H. J. Am. Chem.
Soc. 1969, 91, 3988; (h) Creutz, C.; Taube, H. J. Am. Chem.
Soc. 1973, 95, 1086; (i) Jones, S. C.; Hascall, T.; Norquist,
A. J.; O’Hare, D. Inorg. Chem. 2003, 42, 7707; (j) Jones, S.
C.; Hascall, T.; Barlow, S.; O’Hare, D. J. Am. Chem. Soc.
2002, 124, 11610; (k) Roussel, P.; Cary, D. R.; Barlow, S.;
Green, J. C.; Varret, F.; O’Hare, D. Organometallics 2000,
19, 1071.
3. (a) Katz, T. J.; Rosenmerger, M.; O’Hara, R. J. Am. Chem.
Soc. 1964, 86, 249; (b) Katz, T. J.; Rosenmerger, M. J. Am.
Chem. Soc. 1962, 84, 865.
4. (a) Katz, T. J.; Rosenmerger, M. J. Am. Chem. Soc. 1963,
85, 2030; (b) Katz, T. J.; Mrowca, J. J. J. Am. Chem. Soc.
1967, 89, 1005; (c) Katz, T. J.; Acton, N. J. Am. Chem. Soc.
1972, 94, 3281; (d) Katz, T. J.; Acton, N.; McGinnis, J. J.
Am. Chem. Soc. 1972, 94, 6205.
3.3. Preparation of tricyclo[5.2.1.02,6]deca-2,4-diene
(isodicyclopentadiene)
5-Bromo-8,9-dihydrodicyclopentadiene (5.32 g, 25.0
mmol) and quinoline (4.67 g, 36 mmol) were added in
a round-bottom flask fitted with a distillation apparatus.
The system was heated until 105 °C and at 20 mmHg.
The reaction was carried out until distilled liquid
5. Jones, S. C.; Roussel, P.; Hascall, T.; O’Hare, D. Organo-
metallics 2006, 25, 221.
6. Absolute ethanol is necessary for good yield, use of
technical ethanol low the yield of hydrogenation.
7. (a) Oberhauser, T. J. Org. Chem. 1997, 62, 4504; (b)
Djerassi, C. Chem. Rev. 1948, 43, 271; (c) March, J.
Advanced Organic Chemistry; Wiley & Sons: New York,
1985.
1
stopped. The H NMR of the resulting liquid was simi-
lar to the reported isodicyclopentadiene.3
8. (a) Karplus, M. J. Am. Chem. Soc. 1963, 85, 2870; (b)
Karabatsos, G.; Orzech, Ch. E. J. Am. Chem. Soc. 1965, 87,
560.
4. Conclusions
9. Furniss, B. S.; Hannaford, A. J.; Smith, P. W.; Tatchell, A.
R. Vogel’s Textbook of Practical Organic Chemistry, 5th
ed.; LongMan, 1989, p 422 and 1185.
The title compound, isodicyclopentadiene, was prepared
by an alternate route and 5-bromo-8,9-dihydrodicyclo-