Synthesis of Novel β-lactone from 2-(2,4-dichlorophenoxy)ethenone as novel ketene

synthesis of 2,4-Dichlorophenoxyacetic acid derivatives containing functionalized β-lactone moiety was achieved starting from by a reaction of 2-(2,4-dichlorophenyl)acetic acid, Aldehyde, and Mukaiyama’s reagent in the presence of triethylamine in dichloromethaneat ambient temperature. Th e approach to these valuable heterocyclic scaffolds involves a formal [2π + 2π] cycloaddition between Aldehyde and the 2-(2,4-dichlorophenoxy)ethenone as a novel ketene which was generated in situ and an electrocyclic reaction of a zwitterionic intermediate. Th e βlactone was formed. Th e identification of the ketene was confirmed by reaction with the stable free radical TEMPO (TO•).