Long-range correlations ( n j C,H n > 3 ) in the HMBC spectra of 3-(4-oxo-4H-chromen-3-YL)-acrylic acid ethyl esters

• Autor(es):

  Araya-Maturana, Ramiro (Universidad de Chile. Facultad de Ciencias Químicas y Farmacéuticas. Departamento de Química Orgánica y Fisicoquímica);

  Gavín-Sazatornil, José A. (Universidad de La Laguna. Instituto Universitario de Bio-Orgánica);

  Heredia-Moya, Jorge (Universidad de Chile. Facultad de Ciencias Químicas y Farmacéuticas. Departamento de Química Orgánica y Fisicoquímica);

  Pessoa-Mahana, Hernán (Universidad de Chile. Facultad de Ciencias Químicas y Farmacéuticas. Departamento de Química Orgánica y Fisicoquímica);

  Weiss-López, Boris (Universidad de Chile. Facultad de Ciencias. Departamento de Química).

• Fonte:

  Journal of the Brazilian Chemical Society; volume 16, número 3b, páginas 657-661. Junho 2005.

• Assuntos:

  ¹H and 13C NMR;

  HMBC;

  CIGAR-HMBC;

  IMPEACH-MBC;

  5J C,H, acrylic acid ethyl esters;

  chromone.

• Resumo:

  A systematic study about the long-range correlations observed in the HMBC spectra of a series of cis and trans 3-(4-oxo-4H-chromen-3-yl)-acrylic acid ethyl esters, and 5-hydroxy derivatives, was carried out. The results were compared with those observed in IMPEACH-MBC and CIGARHMBC spectra. An uncommon 5J C,H between the methyl protons and the Ca to the carbonyl group was observed in these systems as well as in ethyl chrotonate. The complete assignments of the ¹H and 13C NMR spectra are provided.

• Acesse o texto completo (Inglês)