[摘要]:A novel and efficient synthesis of 2-aroyl-1,4-diaryl-7,9-dimethyl-7,9-diazaspiro[4.5]deca-1,3-diene-6,8,1 0-triones is described. The reactive 1:1 zwitterionic intermediate, formed by the addn. of PPh3 to diaroylacetylenes, was trapped by a Knoevenagel condensation product prepd. in situ by reaction of N,N-dimethylbarbiturate and arom. aldehydes, to afford the title compds. in excellent yields under mild reaction conditions.