Alkenes, reaction with thallium nitrate

Mercuric salts induce oxidative rearrangement of cyclic alkenes and give cycloalkane carboxaldehydes. Cyclohexene, for example, gave cyclopentane carboxaldehyde (404) in 53% yield. Acyclic alkenes such as 2-butene can also be oxidized with mercuric sulfate and sulfuric acid, giving 2-butanone in this case.566 Thallium nitrate [T1(N03)3] is an important reagent for the oxidative rearrangement of cyclic alkenes.567 The reaction is not restricted to carbocyclic compounds, but can also be applied to heterocyclic compounds as shown by the oxidation of 3,4-dihydro-277-pyran (405) to the dimethyl acetal (406) in 65% yield.568... 

Thallium(III) acetate reacts with alkenes to give 1,2-diol derivatives (see p. 128) while thallium(III) nitrate leads mostly to rearranged carbonyl compounds via organothallium compounds (E.C. Taylor, 1970, 1976 R.J. Ouelette, 1973 W. Rotermund, 1975 R. Criegee, 1979). Very useful reactions in complex syntheses have been those with olefins and ketones (see p. 136) containing conjugated aromatic substituents, e.g. porphyrins (G. W. Kenner, 1973 K.M. Smith, 1975). 

Arylthallium bis(trifluoroacetate)s are converted by successive treatment with KF and BF3 into aryl fluorides.Thallium(iii) nitrate (TTN) readily oxidizes dialkyl sulphides and selenides to the corresponding sulphoxides or selenoxides, and 2-(alkylthio)-l-arylethanones (37) into compounds (38) in methanolic solution.In a modification of the TTN oxidative conversion of aryl alkyl ketones into arylacetic acids, enol ethers derived from the ketones are used instead of the ketones themselves. This reduces the formation of side products. Cyclic aralkyl ketones (39) may be ring-expanded and alkylated to give compounds (40) via treatment of their Wittig-derived alkenes with TTN/ an extrapolation of the basic reaction discovered previously. 

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