Cis Hydroxylation of Alkenes

Osmium tetroxide, Os04. This is undoubtedly the most important compound or complex of osmium, and it was as the tetroxide that osmium was first separated and, as explained on p. 522, gave its name to the element. It is industrially important both in the fine organic chemicals industry (for the cis hydroxylation of alkenes) and in biological chemistry and medicine for the fixation or... 

In his classic work on the cis hydroxylation of alkenes, Criegee used mannitol with osmium(VI) esters (in a 2 1 sugar osmium ratio) in order to complex the metal and thus hydrolyze the ester to the cis diol the nature of the osmium sugar complex was not investigated.480... 

A distorted octahedral, deep red complex of 1,2-diamine (R,R )-trans-l,2-bis(N-pyrrolidino)cyclohexane (L), L-0s04 has been made at low temperatures.103 It is very reactive and is formally a 20e outer valence shell species. The isolation of this and relevant 1,2-diamine complexes throws light upon the mechanism of enantiose-lective dihydroxylation of alkenes noted below. The tetroxide has important commercial use in the stoichiometric and catalytic cis-hydroxylation of alkenes. There has been much discussion of the mechanism, particularly for the enantiospecificity achieved in the presence of cinchona alkaloids or other chiral agents.104... 

T. Kokubo, T.Sugimoto, T. Uchida, S. Tanimoto, M. Okano, The bovine serum albumin-2-phenylpropane-l,2-diolatodioxo-somium(Vl) complex as an enantioselective catalyst for cis-hydroxylation of alkenes, J. Chem. Soc., Chem. Commun., 1983, 769-770. 

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