SciELO - Scientific Electronic Library Online

 
vol.16 issue6AStudy on the determination of lead, cadmium, mercury, nickel and zinc by a rapid column high-performance liquid chromatographyChromatographic determination of riboflavin in the presence of tetracyclines in skimmed and full cream milk using fluorescence detection author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Journal of the Brazilian Chemical Society

Print version ISSN 0103-5053

Abstract

SILVA JR., Luiz F.; SOUSA, Raquel M. F.; FERRAZ, Helena M. C.  and  AGUILAR, Andrea M.. Thallium trinitrate-mediated ring contraction of 1,2-dihydronaphthalenes: the effect of electron-donating and electron-withdrawing groups. J. Braz. Chem. Soc. [online]. 2005, vol.16, n.6a, pp. 1160-1173. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532005000700012.

The oxidation of a series of 1,2-dihydronaphthalenes substituted in the aromatic ring was investigated with thallium trinitrate (TTN) in methanol or in trimethylorthoformate (TMOF) as solvent. In all cases, indans are produced, although the yield varied from excellent to poor, depending on the structure of the substrate. The presence of an electron-donating group in the substrate favors the rearrangement, whereas significant amounts of glycolic derivatives, as well as naphthalenes, were obtained in the oxidation of 1,2-dihydronaphthalenes bearing electron-withdrawing groups, such as Br and NO2. Mechanisms for the formation of each of these products are proposed.

Keywords : ring contraction; oxidation; indans; thallium(III).

        · abstract in Portuguese     · text in English     · pdf in English