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

Journal of the Brazilian Chemical Society

Universidad de La Laguna, Spain¹  Weiss-López, Boris¹  Gavín-Sazatornil, José A.¹  Heredia-Moya, Jorge¹  Universidad de Chile¹  Araya-Maturana, Ramiro¹  Pessoa-Mahana, Hernán¹  Universidad de Chile, Santiago, Chile¹ 

关键词: 1H and 13C NMR;    HMBC;    CIGAR-HMBC;    IMPEACH-MBC;    5J C;    H;    acrylic acid ethyl esters;    chromone;   

DOI  :  10.1590/S0103-50532005000400028

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

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 5JC,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.

【 授权许可】

Unknown