Stereochemical assignment of four diastereoisomers of a maculalactone derivative by computational NMR calculations

Autor(es)

Previdi, Daniel ^[1] ; Nardini, Viviani ^[1] ; Rosa, Mayla Eduarda ^[1] ; Palaretti, Vinicius ^[1] ; Jose da Silva, Gil Valdo ^[1] ; Donate, Paulo Marcos ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, Ave Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Molecular Structure; v. 1178, p. 467-478, FEB 15 2019.
• Citações Web of Science: 0

Resumo

Naturally occurring gamma-butyrolactones and their synthetic analogues display a wide range of bioactivities. Here, the multicomponent reaction of dimethyl 2-benzyl-3-methylenesuccinate with bromobenzene and benzaldehyde catalyzed by cobalt (II) bromide afforded a maculalactone derivative with three stereo genic centers. This reaction presented moderate diastereoselectivity and yielded different proportions of all the four possible diastereoisomers. The anti:anti (majority), anti:syn, syn:anti, and syn:syn diastereoisomers were isolated and characterized by 1D and 2D NMR experiments. Because the stereo chemical assignment of all the diastereoisomers by Nuclear Overhauser Effect Difference (NOEDiff) experiments was not definitive, the H-1 and C-13 NMR chemical shifts were predicted by theoretical calculations with the density functional theory at the B3LYP/6-31G(d) level. The relative configurations of all the four diastereoisomers were assigned by using the CP3 parameter to compare the experimental and the calculated data and by determining the CP3 probability, which provided high level of confidence. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 13/18254-9 - Uso de processos multicomponentes na síntese de novos compostos de interesse farmacológico
• Beneficiário: Paulo Marcos Donate
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/05454-5 - Estudo sobre a síntese de derivados de maculalactonas
• Beneficiário: Mayla Eduarda Rosa Celorio
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 16/04896-7 - Uso de processos multicomponentes na síntese de novos compostos de interesse farmacológico - Parte 2
• Beneficiário: Paulo Marcos Donate
• Modalidade de apoio: Auxílio à Pesquisa - Regular