Functional-Group Reactions

The following table summarizes the reactions of important functional groups. The functional groups are listed alphabetically, followed by a reference to the appropriate text section. 

Hydrolysis to yield a ketone or aldehyde plus alcohol (Sec. 19.10) 

Friedel-Crafts reaction with an aromatic compound to yield an aryl ketone (Sec. 16.3) 

Reaction with a lithium diorganocopper reagent to yield a ketone (Sec. 21.4) 

Reaction with a carboxylic acid to yield an ester (Sec. 21.3) 

Beckmann, B. Geiger, and H. Geiger, Finn. Chem. Letters, 1974, 87. B. Giese, Chem. Ber., 1974, 107,808. 

The chlorobenzonorbornadienes (643) and (644) react very slowly with PhMgBr + CuBr as shown. The stereospecificity is taken as evidence for an ion-pair, rather than a radical mechanism. (643) reacts with magnesium, giving (645) with remarkable stereoselectivity, and (645) can also be made by the stereospecific addition of benzyne to cyclopentadienylmagnesium bromide. Equilibration or selective destruction of the syn-isomer of (645) are justifiably discounted but no explanation of the stereospecificity is offered. Reaction of (645) with DjO occurs with 90% retention of configuration.  

In certain cases low-pressure pyrolysis of trithians (654) gives good yields of thio-ketones, e.g. bicyclo[2,2,l]heptane-2-thione (85%) containing 90% of the thione tautomer, which can be kept at room temperature for several days. The initial percentage of enethiol (1 %) only rises to 7% after five days with concomitant partial trimeri- 

2-Substituted 2-halogenonorbornanes are reduced by tri-n-butyltin hydride with complete loss of stereochemistry.  

Hydrolysis at pH 5 of the exo- and endo-cis-carboxyphosphates (660) reveals carboxyl assistance accelerating the rate by 10 . ° The C—N bond cleavage accompanying Eschweiler-Clark methylation of (661) involves a 1,3-hydride transfer. The conformation of 3-(iV-methylamino)thiocarbonylcamphor is revealed by i.r., u.v., c.d., 4nd dipole moment studies. An imidazolyl bicycloheptanol cinnamate (662) has been prepared as a model for the enzyme chymotrypsin, and the hydroxy-imide (663) is superior to JV-hydroxysuccinimide in effecting (along with DCC) synthesis of peptides.  

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Carboxylic Acid Functional Group Reactions. Polymerization is avoided by conducting the desired reaction under mild conditions and in the presence of polymeriza tion inhibitors. AcryUc acid undergoes the reactions of carboxyUc acids and can be easily converted to salts, acryhc anhydride, acryloyl chloride, and esters (16—17). 

The carboxyl groups of amino acids undergo all the simple reactions common to this functional group. Reaction with ammonia and primary amines yields unsubstituted and substituted amides, respectively (Figure 4.9a,b). Esters... 

Figure 6. Sketch of expected variation of the initial (c0) and residual (cr) concentration of functional groups, reaction conversion , and the ratio ve/Te in end-linked networks as a function of molecular weight of elastomer component M. For discussion see text.

The mineral surface may be considered as a solid source of Lewis and/or BrfSnsted acidity and the reactive sites S as localized acidic or basic functional groups. Reactions involving such sites may be understood in terms of Lewis acid/base or BrfSnsted acid/base interactions ( 1, 5, 6, 8, 38). As the acidity of the reactive sites increases, increasingly weak bases are neutralized and reactive surface complexes (A S) may be formed. The term "acidity" is often used in the broad sense of the word, including both BrjSnsted and... 

The decomposition of 3-phenyloxadiazole is analogous. Unsubstituted oxadiazole is even more unstable and can only be isolated with difficulty (55c). The stability of a disubstituted oxadiazole may decrease if one of the substituents is a functional group. Reactions involving the functional group sometimes take place as expected but frequently lead to the decomposition of the ring. The preparation and properties of such substances will be reviewed in section 5. 

There is a paucity of functional group reactions associated with the pyrrolopyrazines. A few examples may be found within the references describing their syntheses. However, a reaction has been reported which describes the [4 + 2] cycloaddition of pyrrolopyrazines. Ring expansion of 2-phenyl-2//-pyrrolo[3,4-/ ]pyrazine (32) occurs through cyclocondensation of the trimethylsilyl ether (33) with, amongst other dienophiles, methyl acrylate, and a mixture of quinoxalines (34) is obtained in 38% yield (Scheme 2) <86JHC1641>. 

A variety of other carbon-o gen groups have been suggested, including lactones, anhydrides, peroxides, ethers, and esters (14-18). These surfaces oxides have been studied by functional group reactions (18), titration, and infrared spectroscopy (15,... 

Quinolyl compounds activated by sulfur functional groups, reactions of 86MI29 87YGK624. 

Monomers can be joined by means of two principal methods to form polymers, and these methods are used as the broad basis for classification of synthetic polymers. The first of these, condensation, or step-growth polymerization, involves the use of functional group reactions such as esterification or amide formation to form polymers. When each of the molecules involved has only one functional group then the reaction between a carboxylic acid and an alcohol gives an ester (Eq. 20.3). In this equilibrium reaction water removal will help drive the reaction to the right. 

Because this chapter is intended to examine only potentiometric and thermometric methods of functional group analysis, the irreversible methods of analysis of acidic functional groups [reaction of acidic H with CH2N2, LiAlH4, or (BH3)2] are not discussed. The most likely potentiometric proce-... 

Functional group Reaction Result Caramelan Caramelen ... 

No. Name or designation Mp C Formula Functional groups Reaction with H2SO4 References ... 

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