Abstract
Stabilized phosphoranes were synthesized from the reaction between dimethyl acetylenedicarboxylate and amide derivatives in the presence of triphenylphosphine. Dimethylurea containing a phosphorus ylide underwent a smooth reaction in boiling toluene to produce hydantoin and oxo-oxazolidin containing stable phosphorus ylides in good yields. Phosphorus ylides derived from (PhO)3P were not stable and converted to diastereoisomeric phosphonates and phosphorimidate. The nature of the amide derivatives and type of trivalent phosphorus compounds, as well as solvents, determined the distribution of products.