@article{3027328, title = "Improvement on the synthesis of (E)-alk-3-enoic acids", author = "Ragoussis, N. and Ragoussis, V.", journal = "Journal of the Chemical Society, Perkin Transactions 1", year = "1998", number = "21", pages = "3529-3533", publisher = "Royal Society of Chemistry", issn = "0300-922X, 1364-5463", doi = "10.1039/a806173d", abstract = "(E)-Alk-3-enoic acids have been prepared in high yield (85-90%) and excellent stereoselectivity (98-99%) by a modified Knoevenagel condensation of a straight carbon chain aldehyde with malonic acid, in dimethyl sulfoxide (DMSO) or dimethylformamide (DMF) at 100°C, in the presence of piperidinium acetate as catalyst. Condensation of the aldehyde with a monoester of malonic acid, under the above conditions, gave the corresponding ester of (E)-alk-3-enoic acid in high yield (76-82%) and good stereoselectivity (90-92%). Condensation of the aldehyde with cyanoacetic acid gave the β,γ-unsaturated nitrile in moderate yield (35-40%) without stereoselectivity." }