Studies on the Nuclear Magnetic Resonance Spectra of (E)-1-Aryl-3-(2- and 3-thienyl)-2-propenones and Unique Observation of⁴J and⁵J Coupling in Their¹H-¹H COSY

Abstract

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, 4 J and 5 J, are observed in the 1 H-1 H 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.

Crystal structure of (E)-1-(3-chlorophenyl)-3-(furan-2-yl)prop-2-en-1-one

“…For the synthesis of the title compound, see: HanLee et al (2011). For the syntheses of related compounds, see: Inokuma et al (2009).…”