The behavior of 2‐substituted‐1,3‐diphenylpropane‐1,3‐tione toward organophosphorus reagents

The reaction of 2‐benzylidene‐1,3‐diphenylpropanetrione ( 1a ) with phosphorus ylides 2a–c afforded the new phosphonium ylides 4a–c . Trialkyl phosphites 3a–c react with 1a to give the respective dialkyl phosphonate products 5a–c . On the other hand, the olefinic compounds 6 and 7 were isolated from the reaction of 1b with Wittig reagents 2 . Moreover, trialkyl phosphites reacted with 1b to give products 8a–c . Possible reaction mechanisms are considered, and the structural assignments are based on analytical and spectroscopic evidence. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:57–64, 2000