Use este identificador para citar ou linkar para este item: https://locus.ufv.br//handle/123456789/21834
Tipo: Artigo
Título: Assignment of the relative and absolute stereochemistry of two novel epoxides using NMR and DFT-GIAO calculations
Autor(es): Moraes, F. C.
Alvarenga, E. S.
Demuner, A. J.
Viana, V. M.
Abstract: Considering the potential biological application of isobenzofuranones, especially as agrochemical defensives, two novel epoxides, (1aR,2R,2aR,5S,5aS,6S,6aS)- 5-(hydroxymethyl)hexahydro-2,6-methanooxireno[2,3-f]isobenzofuran-3(1aH)-one (9), and (1aS,2S,2aR,5S,5aS,6R,6aR)-5-(hydroxymethyl)hexahydro-2,6-methanooxireno[2,3-f]isobenzofuran-3(1aH)-one (10), were synthesized from the readily available D-mannitol in six steps. The multiplicities of the hydrogens located at the bridge of the bicycle are distinct for epoxides 9 and 10 due to W coupling, and this feature was employed to confirm the assignment of these nuclei. Besides analyses of the 2D NMR spectra, the assignments of the nuclei at the epoxide ring were also inferred from information obtained by theoretical calculations. The calculated 1H and 13C NMR chemical shifts for eight candidate structures were compared with the experimental chemical shifts of 9 and 10 by measuring the mean absolute errors (MAE) and by the DP4 statistical analysis. The structures and relative configurations of 9, and 10 were determined via NMR spectroscopy assisted with theoretical calculations. As consequence of the enantioselective syntheses starting from a natural polyol, the absolute configurations of the epoxides 9 and 10 were also defined.
Palavras-chave: D-mannitol
Enantioselective synthesis
DFT
Diels-Alder
Epoxide
Editor: Journal of Molecular Structure
Tipo de Acesso: Elsevier B.V.
URI: https://doi.org/10.1016/j.molstruc.2018.03.050
http://www.locus.ufv.br/handle/123456789/21834
Data do documento: 15-Jul-2018
Aparece nas coleções:Artigos

Arquivos associados a este item:
Arquivo Descrição TamanhoFormato 
artigo.pdf
  Until 2100-12-31
texto completo620,28 kBAdobe PDFVisualizar/Abrir    Solictar uma cópia


Os itens no repositório estão protegidos por copyright, com todos os direitos reservados, salvo quando é indicado o contrário.