There are two ortho positions and only one para position. So if it were completely random (and there were no meta) the yield would be 66%. The fact that the yield is 57% shows that the methyl group has some steric influence. The effect becomes much greater as the alkyl group is increased in size.
]]>It mentions that primary isotopic effect is seen when the loss of an alpha-hydrogen happens in the slower than the formation of the Wheland-complex. It says this is only the case when the electrophile is a significantly bulkier group.
I’d also like to know how charge-transfer complexes are formed from pi-complexes, but that is a little off-topic and at the risk of digressing I wont talk too much about them (I dont understand them well enough anyway)
]]>There is only one intermediate – the carbocation. Are you referring to the two transition states?
]]>