Reductions and Radical Anions

Show methods to prepare these compounds from alkenes  

Many organic compounds can be reduced by reaction with a source of electrons and a source of protons. (Previous examples include the Clemmensen reduction and the reduction of nitro groups to amino groups described in Chapter 17.) Often this is accomplished 

Several examples of the Birch reduction of substituted benzene derivatives are shown in the following equations. Note that substituents such as alkyl and alkoxy groups prefer to be attached to one of the carbons of the double bonds of the product, while a carboxyl group prefers to be attached to one of the singly bonded carbons. Benzene derivatives with other types of substituents are usually not employed as reactants in the Birch reduction because the substituents are not stable to the reaction conditions. 

0 An electron is transferred from a sodium atom to a benzene molecule. This electron is added to the lowest-energy orbital that is available, a pi antibonding MO in this case. 

The product of the first step 0 A second electron is has an odd number of electrons added to the radical, and a negative charge so it is producing a carbanion. 

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