(Z)-3-Benzoyl-2-[(Z)-1-benzoyl-2-(4-methoxy-phenyl)-vinyl]-2-cyano-4-(4-methoxy-phenyl)-but-3-enoic acid ethyl ester 在
phosphorus pentoxide 作用下,
以
苯 为溶剂,
以67%的产率得到2H-Pyran-4-carboxylic acid,3,5-dibenzoyl-4-cyanotetrahydro-2,6-bis(4-methoxyphenyl)-, ethyl ester