Similarly, now comparing the structure E and the structure of the 4-X-2-Y-heterocycle F of scheme 3, the functional group Y and the substituent X are separated by one single bond and one double bond or simply by a pair of π-electrons. It can be assumed that the substituent electronic effects can be transmitted from carbon 3 bearing the substituent X to the functional group Y at carbon 1 of the benzene. This kind of situation of the structure F where in the substituent electronic effects can be transmitted from carbon 4 bearing the substituent X to the functional group Y at carbon 2 of the hetercycle would be just like that of structure E.