The authors synthesized the title compounds as analogues of previously prepared potential antiphlogistic agents. Starting from appropriate carbonyl compound and alpha-metallated phenylacetic acid the diastereomeric racemate pairs were obtained; they were separated, attributed to erythro/threo-configuration by NMR and finally resolved. The potassium salts of the enantiomers were tested for analgesic and antiinflammatory activity, as well as for acute toxicity. Their action in the carrageenan test has been found to be stereoselective, but relatively poor or of briefly lastening.