Review of Lewis Acids and Bases

We have seen it before, as early as Chapter 1, but in this chapter the curved arrow formalism becomes more important than ever. If you are at all uncertain of your ability to push electrons with arrows, now is definitely the time to sofidify this skill. In the arrow formalism convention, arrows flow from electrons. But be carefiil about violating the mles of valence arrows either displace another pair of electrons or fiU a hole —an empty orbital. 

It is really important to be able to generafize the definition of Lewis bases and Lewis acids. AU electron-pair donors are Lewis bases, and nearly any pair of electrons can act as a Lewis base under some conditions. Similarly, there are many very different appearing Lewis acids—acceptors of electrons. 

The four fundamental reactions we study in this chapter, 8 2, S l, E2, and El, are affected by the reaction conditions as well, of course, as by the structures of the molecules themselves. These four reactions often compete with each other, and it is important to be able to select conditions and structures that favor one reaction over the others. You will rarely be able to find conditions that give specificity, but you will usually be able to choose conditions that give selectivity. 

Alcohols are important starting materials for synthesis—they are inexpensive and easily available. Alcohols can be made even more useful by learning how to manipulate the OH group to make it more reactive— to make it a better leaving group. Several ways to do that are outfined in Section 7.4f. 

Keeping track of your growing catalog of useful synthetic reactions is not easy—it is 

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