Two Neighboring Double Bonds Conjugated Dienes

Another way of producing an allylic organometaUic is Grignard formation. For example, 

Like their alkyl counterparts (Section 8-8), allylic lithium and Grignard reagents can react as nucleophiles. This is useful, because the embedded double bond allows for further functional-group transformations (Chapter 12). 

Show how to accomplish the following conversion in as few steps as possible. (Hint Allylic organometaUic compounds react with ketones in the same manner as ordinary organometaUic reagents.) 

In Summary Alkenes tend to be deprotonated at the allylic position, a reaction resulting in the corresponding delocalized anions. Allylic lithium or Grignard reagents can be made from the corresponding halides. Like their alkyl analogs, allyl organometaUics function as nucleophiles. 

Hydrocarbons with two double bonds are named dienes 

---

Two Neighboring Double Bonds Conjugated Dienes CHAPTER 14... 

---