DARZENS REACTION AS A CONVENIENT METHOD FOR THE SYNTHESIS OF ALPHA-CHLOROKETONES, ALPHA-CHLOROEPOXIDES, AND SYMMETRICALLY SUBSTITUTED DIOXINES

The Darzens reaction of dichloroacetophenone (DCAP) with substituted b enzaldehydes has been studied. The structure of the products was shown to depend on the phenyl group substituents. Reaction of benzaldehyde, 4-bromo-, and 2,4-dichlorobenzaldehydes results in 1-phenyl-3-aryl-3- chloropropane-1,2-diones (2a-c), reaction of para- or meta-nitrobenzal dehydes yields 1-phenyl-2-chloro-3-aryl-2,3-epoxypropane-1-ones (3a, b ). Upon the introduction of an alkoxy group into the phenyl ring of be nzaldexyde and/or dichloroacetophenone, symmetrically substituted diox ines were obtained (6a-c). The structure of the reaction products has been established by single crystal X-ray investigations.