The absolute configuration of (+)-α-methyl-β-dimethylaminopropiophenone (Ia) was found to be S by chemical correlation with R(-)-α-methyl-β-alanine. The absolute configuration of (+)-α-methyl-β-piperidino- and of (-)-α-methyl-β-morpholinopropiophenone (Ib and Ic) was found to be S and R, respectively, by comparison of their ORD spectra with that of the keto-base (Ia). © 1969.