Interchange, functional group

Functional group interchange transforms (FGI) frequently are employed to allow simplifying skeletal disconnections. The examples 9 => 10 and 11 => 12 + 13, in which the initial FGI transform plays a critical role, typify such processes. 

Functional Group Interchange. (FGI) The replacement of one functional group by another. 

Figure 3.4 The synthesis of ibuprofen is initiated by a Friedel-Crafts acylation of an aUcyl-substituted benzene ring. The resulting ketone is then reduced to an alcohol with sodium boro-hydride. The alcohol functionality then undergoes a functional group interchange by conversion to a bromide. In turn, this permits the introduction of an additional carbon atom in the form of a nitrile introduced via an 8, 2 nucleophilic displacement. This is then hydrolyzed to give the target molecule.

The following functional-group interchange is a useful synthesis of aldehydes. 

A metathesis reaction is defined as a chemical transformation in which atoms from different functional groups interchange with one another, resulting in the redistribution of functionality yielding similar bonding patterns for both molecules [6]. 

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