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Cyclic unsaturated compounds

Communication 29. Pentamethylcyclopentadienes

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  1. 1.

    The methylation of sodium 1,2,3,4-tetramethylcyclopentadienyl in liquid ammonia gives a mixture that analyzes 88% of 1,2,4,5,5-pentamethylcyclopentadiene and 12% of 1,2,3,4,5-pentamethylcyclopentadiene. The methylation of the latter leads to the formation of hexamethylcyclopentadiene in good yield.

  2. 2.

    We were the first to discover the 1,3-migration of a methyl group in the cyclopentadiene ring. At 425–500°, 1,2,4,5,5-pentamethylcyclopentadiene is smoothly isomerized to 1,2,3,4,5-pentamethylcyclopentadiene. The coupling of two consecutive intramolecular acts of 1,2-migration of the methyl group is considered to be the mechanism of such isomerization. The pyrolysis of the readily available 1,2,4,5,5-pentamethylcyclopentadiene is a convenient preparative method for the synthesis of 1,2,3,4,5-pentamethylcyclopentadiene.

  3. 3.

    The obtained dienes were characterized by the adducts with maleic anhydride and their derivatives. A study was made of the stereochemistry of the condensation products of 1,2,3,4,5-pentamethylcyclopentadiene with maleic anhydride. The 7-syn isomer (with respect to the double bond) predominates in the mixture of epimers formed at the C7 center of the bicyclo[2.2.1]heptene system.

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Literature cited

  1. 1.

    V. A. Mironov, T. M. Fadeeva, V. S. Pashegorova, A. U. Stepanyants, and A. A. Akhrem. Izv. Akad. Nauk SSSR, Ser. Khim.,1968, 423.

  2. 2.

    L. deVries, J. Org. Chem.,25, 1838 (1960).

  3. 3.

    V. A. Mironov, T. M. Fadeeva, E. V. Sobolev, and A. N. Elizarova, Zh. Obshch. Khim.,33, 84 (1963).

  4. 4.

    V. A. Mironov, E. V. Sobolev, and A. N. Elizarova, Tetrahedron,19, 1939 (1963).

  5. 5.

    R. Ya. Levina, N. N. Mezentseva, and E. G. Treshcheva, Dokl. Akad. Nauk SSSR,104, 549 (1955).

  6. 6.

    R. Riemschneider and E. B. Grabitz, Monatsh. Chem.,89, 748 (1958).

  7. 7.

    S. McLean and P. Haynes, Tetrahedron,21, 2343 (1965).

  8. 8.

    V. A. Mironov, E. V. Sobolev, and A. N. Elizarova, Izv. Akad. Nauk SSSR, Ser. Khim.,1964, 1607.

  9. 9.

    V. A. Mironov, S. N. Kostina, E. V. Sobolev, and A. N. Elizarova, Izv. Akad. Nauk SSSR, Ser. Khim.,1964, 864.

  10. 10.

    V. A. Mironov, S. N. Kostina, and A. N. Elizarova, Izv. Akad. Nauk SSSR, Ser. Khim.,1964, 875.

  11. 11.

    K. Alder and R. Muders, Chem. Ber.,91, 1083 (1958).

  12. 12.

    B. F. Hallam and P. L. Pauson, J. Chem. Soc,1958, 646.

  13. 13.

    B. A. Kazanskii, E. V. Sobolev, V. T. Aleksanyan, L. A. Nakhapetyan, and M. Yu. Lukina, Dokl. Akad. Nauk SSSR,159, 839 (1964).

  14. 14.

    J. W. de Haan and H. Kloosterziel, Rec. Trav. Chim.,84, 1594 (1965).

  15. 15.

    V. A. Mironov, T. M. Fadeeva, and A. A. Akhrem, Dokl. Akad. Nauk SSSR,174, 852 (1967).

  16. 16.

    V.F. Bystrov, A. U. Stepanyants, and V. A. Mironov, Zh. Obshch. Khim.,34, 2886 (1964).

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See [1] for Communication 28 in the given series.

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 609–621, March, 1968.

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Mironov, V.A., Pashegorova, V.S., Fadeeva, T.M. et al. Cyclic unsaturated compounds. Russ Chem Bull 17, 588–597 (1968).

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  • Adduct
  • Pyrolysis
  • Double Bond
  • Anhydride
  • Diene