In Equation A, the first step of a Markovnikov addition of HBr is shown, example from "The Language of Organic Chemistry"®. This scheme directly leads to the most stable carbocation. If you move your mouse over the scheme, you will see a conventional curved arrow scheme. It reveals an inherent weakness because it is ambigious as to what the product might be. What follows is a discussion of carbocation stability. That is, in order to interpret the meaning of the curved arrows, you have to know what the intermediate will be.

Click on the "Eq. A" to see the complete scheme.

In Equation C, one substitutent is changed, but you can still predict the correct intermediate. The major product is different. Move your cursor over the scheme to see how the conventional curved arrows are still the same.

Eq. B

Eq. C

Equation D shows an electrophilic aromatic substitution reaction. Because two substituents are present, this problem is more ambiguous than the others. It can be difficult for a novice chemist to predict the product of this reaction. Move your cursor over the scheme to see how that step is represented in "The Language of Organic Chemistry".

The Value of Pre-Bonds in "The Language of Organic Chemistry"

Eq. D

Equation B extends Equation A to additional substitutents. The curved arrows show the intermediate that forms. Move your cursor over the scheme to see how that step would be represented with conventional curved arrows.