On the mechanism of catalytic asymmetric dihydroxylation (AD) of alkenes

Evidence in support of the asymmetric dihydroxylation (AD) of alkenes to proceed possibly by a trigonal bipyramidal structure in which OsO4 is coordinated independently to the bridgehead nitrogen of bisalkaloid derivatives and not through a hexacoordinated mu-oxo-bridged bisosmium (VIII) is provided. Roth the quinuclidine moieties of the ligand are independently coordinated to one molecule of osmium tetroxide; however, in catalytic AD reaction only one of the osmium tetroxide reacts with the olefin.