What Are Functional Groups

At this point, our concern is only pattern recognition—that is, how to recognize these five functional groups when you see them and how to draw structural formulas of molecules containing them. 

Finally, functional groups serve as the basis for naming organic compounds. Ideally, each of the 10 million or more organic compounds must have a name that is different from every other compound. 

Functional Group Name of Group Present In Example Name of Example 

0 II —c—OH carboxyl carboxylic acids 0 II CHjCOH Acetic acid 

The functional group of an alcohol is an —OH (hydroxyl) group bonded to a tetrahedral sj hybridized) carbon atom. In the general formula that follows, we use the symbol R to indicate either a hydrogen or another carbon group. The important point in the general structure is that the —OH group is bonded to a tetrahedral carbon atom  

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What are functional groups Why is it logical and useful to classify organic compounds according to their functional groups ... 

What does functional-group polarity mean with respect to chemical reactivity Because unlike charges attract, the fundamental characteristic of all polar organic reactions is that electron-rich sites react with electron-poor sites. Bonds are made when an electron-rich atom shares a pair of electrons with an electron-poor atom, and bonds are broken when one atom leaves with both electrons from the former bond. 

Hydroboration-oxidation of enecarbamates with borane-dimethylsulfide complex gives reasonable yields of /i-hydn > xycarbarn ales (equation 28) with some diastereoselectivity, depending upon what other functional groups are present in the starting material152. 

What two functional groups are Created in phthalamic acid ... 

Given a line formula, such as -— (pentane), write the complete structure and clearly show the arrangement of atoms in the molecule. Tell how many hydrogens are attached to each carbon, what the molecular formula is, and what the functional groups are. 

Nonactin and valinomycin each contain only two different types of functional groups. What two functional groups are present in nonactin In valinomycin ... 

The choice of a reducing agent usually depends on what other functional groups are present. Each reducing agent reduces certain groups and not others. This type of... 

Ester synthesis is often accomplished best by the reaction of an alcohol with an acyl chloride or anhydride. These reagents avoid the use of a strong acid, as is needed for acid-catalyzed esterification. A strong acid may cause side reactions depending on what other functional groups are present. 

Reductions like those shown in Equations 17.1-17.4 are commonly effected by either catalytic or chemical methods. Sometimes both techniques can be used, but one of them will usually be preferred for a given substrate, depending upon what other functional groups might be present in the molecule. A brief discussion of these methods will help enable you to understand the basic differences. 

Consider what other functional groups are present which might offer a route to any of the components, e.g. hydroxyl groups (hydroxyl value), free acidic or basic groups that can be titrated, ester groups (saponification value) or polyalkenoxy chains (colorimetry, NaTPB titration of barium complexes), etc. 

Acid chlorides other than oxaiyl chloride (ClCOCOCl) and even acid anhydrides (such as trifluoroacetic anhydride [(Cp3C0)20] can be used in the Swern oxidation. The choice is often dependent upon what other functional groups are present. 

Notice that the by-products of the reaction are Cl and H3O+ which, together, represent an aqne-ous solution of HCl. The build-up of acid can often prodnce nndesired reactions (depending on what other functional groups might be present in the componnd), so pyridine is nsed to remove the acid as it is produced ... 

Reaction Summary Road Maps, found at the ends of Chapters 8, 9, 11, 12, 13, 15,17,19, 20, and 21, provide one-page overviews of the reactivity of each major functional group. The Preparation maps indicate the possible origins of a functionality—that is, the precursor functional groups. The Reaction maps show what each functional group does. In both maps, reaction arrows are labeled with particular reagents and start from or end at specific reactants or products. Section numbers indicate where the transformation is discussed in the text. 

For molecules similar to safrole or allylbenzene we take the work done on any terminal alkene such as 1-heptene, 1 octene. Another term to look for is olefin which is a term for a doublebond containing species. What we then look for are articles about these olefins where the functional groups we are looking for are formed. Articles with terminology like methyl ketones from (P2P), ketones from , amines from etc. Or when we want to see about new ways to aminate a ketone (make final product from P2P) we look for any article about ketones where amines are formed. Sound like science fiction to you Well, how do you think we came up with half the recipes in this book It works ... 

The reactivity of alkylthiazoles possessing a functional group linked to the side-chain is discussed here neither in detail nor exhaustively since it is analogous to that of classical aliphatic and aromatic compounds. These reactions are essentially of a synthetic nature. In fact, the cyclization methods discussed in Chapter II lead to thiazoles possessing functional groups on the alkyl chain if the aliphatic compounds to be cyclized, carrying the substituent on what will become the alkyl side chain, are available. If this is not the case, another functional substituent can be introduced on the side-chain by cyclization and can then be converted to the desired substituent by a classical reaction. 

In the preceding chapter the special stability of benzene was described along with reac tions in which an aromatic ring was present as a substituent Now we 11 examine the aromatic ring as a functional group What kind of reactions are available to benzene and Its derivatives What sort of reagents react with arenes and what products are formed m those reactions ... 

In particular we thought it would be useful to include cross-references of functional group transformations and an experimental procedure, so that the reader will be able to evaluate the reaction conditions at a glance for instance is this reaction carried out at room temperature or at 200 C For 1 h or 5 days Are special catalysts required How is the reaction worked up, what yield can be expected ... 

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