ORGANOPHOSPHORUS CHEMISTRY .24. WITTIG REACTION OF BETA-AROYLACRYLIC AND CINNAMIC-ACIDS

The Wittig reaction of β-aroylacrylic-(2b, c) and cinnamic (4b) acids has been investigated. Depending on the experimental conditions, reaction of 2b, c with alkylidene phosphoranes (1a, b) gives the respective complex ylides 3b-e and/or the dihydrofurans (7), whereas, with benzoylmethylenetriphenylphosphorane (1c), ylide 3f or 3g is only formed. On the other hand, the reaction of 4b with 1a, b proceeded only in ethylacetate, yielding the ylides 9, accompanied by the decarboxylation of the acid. However, compound 4b did not react with 1c, under the above experimental conditions. Structural assignments are based on analytical and spectroscopic results as well as possible reaction mechanisms are annotated. © 1992, Taylor & Francis Group, LLC. All rights reserved.