Studies on the Nuclear Magnetic Resonance Spectra of (E)-1-Aryl-3-(2- and 3-thienyl)-2-propenones and Unique Observation of<sup>4</sup>J and<sup>5</sup>J Coupling in Their<sup>1</sup>H-<sup>1</sup>H COSY
作者:In-Sook HanLee、Hyun-Ju Jeon、Chang-Kiu Lee
DOI:10.5012/bkcs.2011.32.2.687
日期:2011.2.20
$^1H$ and $^13}C$ NMR spectra of series of (E)-1-aryl-(2- and 3-thienyl)-2-propenones, that are aldol condensation products between 2- and 3-thiophenecarbaldehydes and m- and p-substituted acetophenones, were examined to make complete assignments of the chemical shifts. Long range couplings, $^4J$ and $^5J$, are observed in the $^1H-^1H$ COSY of both 2- and 3-thienyl compounds, which makes the elucidation of the conformation in solution possible. In contrast, the 2-furyl analogue shows the long range coupling phenomena, but the 3-furyl and phenyl analogues do not show similar phenomena.
一系列(E)-1-芳基-(2-和3-噻吩基)-2-丙烯酮的$^1H$和$^13}C$ NMR谱,这些化合物是2-和3-噻吩甲醛与间位和对位取代的乙酰苯酮之间的羟醛缩合产物,被研究以完成化学位移的完全归属。在2-和3-噻吩基化合物的$^1H-^1H$ COSY中观察到了长程耦合,$^4J$和$^5J$,这使得在溶液中阐明构象成为可能。相比之下,2-呋喃类似物显示出长程耦合现象,但3-呋喃和苯类似物没有显示出类似现象。