The reaction of dialkyl acetylenedicarboxylates with the N-H acid 4-phenyl-[1,2,4]triazolidine-3,5-dione in the presence of trialkyl(aryl) phosphites at reflux temperature led to the title phosphonato ester derivatives. The configurations of the compounds were determined (2R*, 3S* and mirror image) using the coupling constants and the Karplus equation.

Stereoselective Synthesis of Dialkyl 2-(Dialkoxyphosphoryl)-3-(3,5-dioxo-4-phenyl-[1,2,4]triazolidin-1-yl) Succinates -[via multicomponent reaction of acetylenedicarboxylates (III) with the N-H acid triazolidine-dione (I) in the presence of phosphites (II)]. -(MOHEBAT*, R.; MOGHADDAM, M. I.; MOTLAGH, R. A.; HASSANABADI, A.; KALAMI-YAZDI, M.; J. Chem. Res. 35 (2011) 10, 564-567, http://dx.doi.org/10.3184/174751911x13162731136181 ; Dep. Chem., Islamic Azad Univ., Yazd, Iran; Eng.) -H. Toeppel 11-174