Abstract
Triphenylphosphine reacts with dimethyl methoxymalonate in the presence of alkyl propiolates or dialkyl acetylenedicarboxylates to produce trialkyl 3-(1,1,1-triphenyl-λ5-phosphanylidene)-1-propene-1,1,2-tricarboxylates or tetraalkyl 3-(1,1,1-triphenyl-λ 5-phosphanylidene)-1-propene-1,1,2,3-tetracarboxylates in good yields.