Abstract

The addition of dialkyl phosphites or diphenylphosphine oxide to the triple bond of dialkyl acetylenedicarboxylate may result in mono- and/or bisadducts. The ratio of the products may be influenced by the molar ratio of the reactants and the conditions (temperature of microwave irradiation and reaction time). Stereospecific ³J_PP couplings were utilized in the assignments to the meso and racemic forms of the bisadducts. The bis(dialkylphosphonyl)-succinates were formed as a mixture of the corresponding meso form and racemate, while bis(diphenylphosphinoyl)-succinate was obtained as a racemate. The ³¹P–¹²CH–¹³CH–³¹P spin system of bis(dialkylphosphonyl)-succinates was subjected to a detailed NMR analysis supported by simulation.

Keywords: Dialkyl acetylenedicarboxylate, dialkyl phosphite, diphenylphosphine oxide, addition, microwave.