Olefins oxidation with thallium nitrate

Oxidation and Reduction.—Oxidative rearrangement of olefins with thallium(m) nitrate in methanol provides a simple synthesis of aldehydes and ketones in high yields. Cleavage of the intermediate thallium compound proceeds via a transition state with high carbonium ion character, which leads either to carbonyl compounds (354) by Wagner-Meerwein rearrangement or to glycol methyl ethers (355). ... 

Oxidation of olefins Olefins are oxidized rapidly by thallium(lll) nitrate in methanol at room temperature to aldehydes or ketones. Rearrangement is the exclusive or predominant pathway with olefins in which at least one of the substituted groups has a high migratory aptitude. 

Oxidative rearrangements, via oxythallation, have been improved in yield and selectivity by the use of thallium(iii) nitrate supported on clay rather than in methanolic solution. Thus, cyclohexene gave an 85% yield of dimethoxymethyl-cyclopentane while 1-tetralone, which normally gives a complex mixture of products, gave a 1 1 mixture of methyl indane-l-carboxylate and 2-methoxytetralone. An efficient, large-scale procedure for the direct cis-dihydroxylation of olefins has been reported. The oxidant is t-butyl hydroperoxide and the catalyst osmium tetroxide, with the reaction conducted under alkaline conditions (E%N OH ), so facilitating a rapid turnover of catalyst via enhanced hydrolysis of the osmate esters. The method appears to be more advantageous for the more substituted olefins than the Hofmann and Miles procedure. 

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