E and Z stereoisomers of compounds of the phthalide series

  • L. M. Pisarenko
  • A. B. Gagarina
  • N. N. Sveshnikov
Physical Chemistry Structure And Physicochemical Properties Of Molecules
  • 56 Downloads

Abstract

The stereospecific position of the H4 proton in the PMR spectra of 3-benzyl-idenephthalides identifies unambiguously the E and Z isomers in a mixture. The IR spectra of off-planar deformation vibrations of the C=C bond in the 990–970 cm−1 region have strong absorption bands, assigned to the E and Z isomers. The strong short-wave band (260 nm) for 3-benzylidenephthalides, having only one benzene ring in the indan moiety, suggests the presence of the E form (ε=28,000). The long-wave absorption band at 390–430 nm belongs to the Z isomers (ε=21,000–31,000). 3-Benzylidenephthalides which have no carbonyl groups in their molecules, show fluorescence (λf1=540–560 nm in EtOH).

Keywords

3-benzylidenephthalides E and Z isomers PMR, IR, and UV spectra 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature cited

  1. 1.
    R. K. Howe, J. Org. Chem.,38, No. 24, 4164 (1973).Google Scholar
  2. 2.
    H. E. Schroeder, F. B. Stilmar, and F. S. Palmer, J. Am. Chem. Soc.,78, 446 (1956).Google Scholar
  3. 3.
    S. V. Vinogradova, V. V. Korshak, S. I. Salazkin, and G. Sh. Chelidze, Zh. Prikl. Khim.,44, 1389 (1971).Google Scholar
  4. 4.
    J. Berti, Gazz, Chim. Ital.,86, 655 (1956).Google Scholar
  5. 5.
    V. I. Nikulin, and L. M. Pisarenko, Izv. Akad. Nauk, Ser. Khim., No. 3, 637 (1986).Google Scholar
  6. 6.
    V. I. Nikulin and L. M. Pisarenko, Izv. Akad. Nauk, Ser. Khim., No. 4, 943 (1990).Google Scholar
  7. 7.
    L. J. Bellamy, The Infrared Spectra of Complex Molecules, 1st edn., Wiley, New York (1954).Google Scholar
  8. 8.
    J. Derkash and F. Langer, Monatsch.,86, 924 (1955).Google Scholar
  9. 9.
    G. V. Gobov, Opt. Spektrosk.,15, 362 (1963).Google Scholar

Copyright information

© Plenum Publishing Corporation 1992

Authors and Affiliations

  • L. M. Pisarenko
  • A. B. Gagarina
  • N. N. Sveshnikov

There are no affiliations available

Personalised recommendations