1-Heptene osmium tetroxide

With diamine (25), 1-heptene afforded (/ )- ,2-heptanediol as the major ixoduct (86% ee) in 75% yield by this procedure but, curiously, oxidation of ( )-stilbene proceeded with lower optical yield (34% ee). Particularly efficient enantioface differentiation was achieved in the reaction of ( )-l-phe-nylpropene with a stoichiometric amount of osmium tetroxide in the presence of 1 mol equiv. of (-)-(27) when essentially optical pure (>99% ee) (15,2S)-l-phenylpropane-l,2-diol was obtained in 73% yield. This procedure is effective for mono-, ( )-di- and tri-substituted alkenes, with enantioface selection being as shown in Scheme 2 but, notably, the oxidation of (Z)-alkenes does not give satisfactory optical yields. 

The dihydroxylatiOTi of terminal aliphatic n-alkenes (propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene) catalyzed by osmium tetroxide, a powerful method to enantioselectively introduce chiral centres into organic substrates, has been computationally studied by the hybrid QM/MM IMOMM-(B3LYP MM3) method. The analysis of the results, in particular the partition of the total IMOMM energy into its components, allows the responsibility for the selectivity to be identified [690]. 

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