Сharacterization and stereochemistry of alkyl 2-chloro- 3-formylacrylates: experimental NMR and theoretical DFT studies
T.M. Barhoumi-slimi, M.T. Ben dhia, M. Nsangou, M.M. El gaied, M.R. Khaddar
Ключевые слова: synthesis, Vilsmeier reaction, stereoisomerism, stereoselectivity, cyclization, NMR, NOEDIFF, B3LYP
Страницы: 266-271
Аннотация
The synthesis of alkyl 2-chloro-3-formylacrylates 1 from alkyl pyruvates was carried out using Vilsmeier reaction. The reaction is highly stereoselective and leads to a 95:5 mixture of <i>Z</i> and <i>E</i> stereoisomers. Both stereoisomers were characterized by <sup>1</sup>H and <sup>13</sup>C NMR. In CDCl<sub>3</sub> solution, the NMR data, particularly the NOEDIFF experiments, show that the major species formed is the <i>Z</i> stereoisomer. Heating compound 1 in THF at reflux afforded the cyclic product 2 in 90 % yield. The interpretation of the experimental data were further supported by DFT/B3LYP calculations.
|
