Cyclohexene ruthenium tetroxide

Although aldehydes are obtained from the cleavage of double bonds by ruthenium tetroxide under neutral conditions (Section 3.8.3.4), carboxylic acids are produced under alkaline or acidic conditions. For example, the oxidation of cyclohexene by Ru04 under alkaline conditions has been reported to give adipic acid in yields of 86-95%. ... 

Olefins, see also Catalytic method (p. 989). Djerassi and Engle report one experiment on the oxidation of phenanthrene with ruthenium tetroxide in carbon tetrachloride the reaction mixture contained considerable starting material and a small amount of phenanthrenequinone. Berkowitz and Rylander oxidized cyclohexene in the same way and obtained adipaldehyde in low yield as the only isolated product they regard the method as unsatisfactory for the production of aldehydes and acids because these substances are strongly adsorbed on the ruthenium dioxide formed. 

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