Studies in this Laboratory on the Favorskir rearrangement'made it quite clear that the synthesis of haloketones of type I (R1, Rp, RE= H or alkyl) is not at present very satisfactory. Direct halogenation of the parent ketone (cf. 11) suffers from two major drawbacks: It is necessary to utilize a source of positive halogen which may not be compatible with the presence of certain functional groups in the molecule (eg, double bonds, phenolic rings), ...