title: Synthesis of substituted stilbenes via the Knoevenagel condensation.
abstract: Knoevenagel condensations between aldehydes and substrates containing active methylene groups were carried out in ethanol at room temperature, in the presence of potassium phosphate, to afford unsymmetrical olefins. These condensations have been shown to afford only the E-isomers in greater than 80% yields. Salicylaldehyde first produces the Knoevenagel condensation products, which undergo a subsequent heterocyclization to give coumarin derivatives. The structures of the synthesized compounds were established on the basis of UV, IR, MS and NMR spectroscopy.
authors.affiliation: Department of Chemistry, College of Science, King Faisal University, P.O. Box 1759, Hofuf 31982, Saudi Arabia. sshihry@kfu.edu.sa
authors.forename: Shar Saad
authors.initials: SS
authors.lastname: Al-Shihry
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008956:Models, Chemical; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013267:Stilbenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D013267:Stilbenes