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Trabajo presentado en el XXX European Conference on Molecular Spectroscopy (XXX EUCMOS), celebrado en Florencia (Italia), del 29 de agosto al 3 de septiembre de 2010

A series of carboxyalkenyl-, aminocarbonylalkenylphosphonic, and alkenylbisphosphonic derivatives has been synthesized. The synthesis of 2-ethoxycarbonylvinylphosphonates has been improved with a yield of 73% and an E/Z isomer ratio of 57/43. The separation of both isomers and their hydrolysis to the corresponding phosphonic acids have been studied. The synthesis of 2-ethoxycarbonyl-1-propenylphosphonates has been investigated, obtaining a global yield three times higher than that previously reported, and both E/Z isomers have been separated with a yield of 97.5%. Total and selective hydrolysis to the corresponding phosphonic acids have also been studied. By the appropriate choice of reaction conditions the 2-cyanovinylphosphonate esters can be selectively and partially hydrolyzed to the 2-aminocarbonylvinylphosphonic acids. UV, IR, Raman, and 1H, 13C and 31P NMR spectroscopic studies have been performed in these compounds. Dipole moments and C=C/P=O conformational populations have been calculated theoretically by ab initio methods. The effect of solvent polarity on the conformational population has been observed by IR spectroscopy, disclosing two C=C/P=O conformers. Intramolecular hydrogen bonds have been found in (Z)-2-carboxy-1-propenyl and (Z)-2-carboxyvinylphosphonic acids. Experimental and theoretical results have been compared and show very good agreement.

Kröhnke condensation of several cycloimmonium salts with p-dimethylaminobenzaldhyde has been studied. X-Ray diffraction, IR and Raman spectra, 1H-and 13C-NMR and UV spectra of the products are discussed, being compared, when necessary, with the starting pyridinium salts. All compounds showed the Z configuration, corresponding to the more stable structure, except one, in which steric factors were predominant.