Transformation of the allylic amine of monosubstitutedolefins into the aryl ketimine derivatives resulted in consistent higher anti diastereofacial selectivity in the osmium-catalyzed dihydroxylation reactions, compared to the selectivities obtained from commonly used allylic amino derivatives such as N-acyl, N-Boc or N,N-dibenzyl. The anti selectivity ranged from 3:1 to 7:1 in dry THF and the best