AbstractsChemistry

As a test of Taft's δ° hypothesis the rates of solvolysis of benzyldimethylcarbinyl chloride, and twelve m- and p-substituted derivatives, have been measured in methanol at 66.5°C [FORMULA] The results, analysed by means, of the Hammett equation show that the effect of the aryl substituents on the reactivity is essentially inductive, any Ar-Y resonance interactions being effectively inhibited by the interposed methylene group. The substituent constants derived from this reaction series agreed with Taft's δ° values, within the precision of the latter, with the exception of the meta-methoxyphenyl substituent. This deviation is explained in terms of a dipole-dipole interaction which is possible as a result of the geometry of the system. Also studied were the rates of elimination of the compounds, in sodium methoxide solutions, to give olefins II and III. A Hammett analysis of the rates enabled conclusions regarding the nature of the transition states leading to the two olefins, to be drawn.