The radiochemical and stereochemical consequences of the deamination, accompanied by phenyl migration, of Dand L-erythro- 1-amino-1,2-diphenyl-( 1- phenyl-C/sup 14/)propanol-2 (IV) were studied. It is established that the major products, alpha or beta -benzhydryl-phenyl-C 4 methyl ketone (V) were formed with an average of 73.5% inversion and 26.5% retention of configuration at the migration termini. There was no alpha -phenylpropiophenone formed, thus establishing that no methyl migration occurred during these rearrangements. These results exclude the intervention of initially formed bridged ion intermediates in the deamination of IV. Similar studies were conducted upon two modifications of stereospecifically phenyl-labeled D-2-amino- 1, 1- dlphenylpropane (VII), which underwent deamination to yield L -(+)-threo-1,2- diphenylpropanol-1 (55%, threo-VII) and D-(+)-erythro-1,2-diphenylpropanol-1 (11%, erythro-VIII), 6--7% of olefins and 25--27% of materials which were not identified. These results indicate open carbonium ion formation during the deamination of VII, and are best interpreted in terms of ground-state control of the intermediate open ions. The absolute configuration of D-(--)-phenylglycine was confirmed through the series of reactions just discussed by the conversion of (+)-aminodesoxybenzoin to (--)-2-amino-1, 1,2-triphenylethanol. The radiochemical results serve to establish the configurations of D-(+)- and L-(--)- 2-amino- 1, 1-diphenylpropane (VII). (auth)