The enantiomorphs of norketamine, 2-(o-chlorophenyl)-2-aminocyclohexanone, were synthesized and screened for biological activity. Resolution was achieved by fractional crystallization of the tartrate salts. Stereochemical purity was determined using standard GC or GC-MS analysis. Preliminary pharmacological evaluations revealed that intraperitoneally injected dextrorotatory norketamine caused a greater duration of loss of righting reflex in mice than the levorotatory isomer.