Synthesis of e-and z-o-methoxy-substituted 2,3-diphenyl propenoic acids and its methyl esters

摘要

A series of stereoisomeric o-methoxy-substituted 2,3-diphenyl propenoic acids and their methyl esters have beeen synthesized.The E isomers were prepared by a modified Perkin condensation (substituted benzaldehyde,phenylacetic acid,Et_3N/acetic anhydride).The difficult to access Z isomers were obtained convenient-ly in good yields when the appropriate coumarin derivatives were allowed to react with KOH and CH_3I in DMSO.