A Facile Synthesis of Novel and Stable Phosphorus Ylides Containing 2-Aryl-1,3-Dioxane-4,6-Dione

The reaction between dialkyl acetylene dicarboxylate and 2-aryl-1,3-dioxane-4,6-dione derivatives in the presence of triphenylphosphine in ethyl acetate led to stable phosphorus ylides in good yields. These stabilized phosphorus ylides exist as a mixture of two geometrical isomers as a result of restricted rotation around the carbon–carbon partial double bond. The ¹H NMR variable temperature spectra for 3c are studied and the results are reported.