Synthesis A Beginning

ANSWER Formation of the more stable tertiary carbocation rather than the much less stable primary carbocation inevitably leads to the single product observed, /er/-butyl alcohol. 

What does simple mean It means that no special factors such a resonance stabilization can be present—a simple carbocation is one that is not significantly delocalized by resonance. 

Organic chemistry is not only understanding how reactions occur. A very important part of chemistry is the use of those reactions to make molecules. The construction of target molecules from smaller pieces is called synthesis, and we are now able to do a surprising amount of this kind of thing. Let s just take stock of what kinds of transformations we can do—of what kinds of molecules we can make out of other kinds of molecules. 

The addition of hydrogen halides to alkenes gives us a way to make allg l bromides, chlorides, and iodides (fluorides don t work very well) as long as we have the appropriate starting alkene. We will have to be careful when using unsymmetrical alkenes, because there is a choice to be made here. As you saw in Section 3.18, the addition of HX will only lead to the more substituted alkyl halide, as the regiochem-istry of the addition is controlled by the stability of the intermediate carbocation. 

We can also make alcohols through the acid-catalyzed addition of water to alkenes (Section 3.19). 

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