Carbonyl compounds amide hydrolysis

Moreover, the carbonyl groups are represented in the numerous derivatives of carboxylic acids, namely amides, imides, and so forth. There are no derivatization methods for these compounds at present (excluding reduction), which are based on the reactions of the carbonyl group. Nevertheless, the amides react with (CH3)3SiCF3 in a manner similar to other carbonyl compounds. The hydrolysis of intermediate O-TMS derivatives followed by dehydration leads to the low boiling a-trifiuoromethyl enamines... 

In the case of nicotinamide, the color yield is often low. This problem can be circumvented by either hydrolysis to nicotinic acid or by conversion of the amide to a fluorescent compound. Treatment of nicotinamide with methyl iodide yields the quaternary ammonium salt, /V-methyl nicotinamide (5). Reaction of this compound with acetophenone yields a fluorescent adduct (49). Other carbonyl compounds have also been used (50—54). 

Nitriles are similar in some respects to carboxylic acids and are prepared either by SN2 reaction of an alkyl halide with cyanide ion or by dehydration of an amide. Nitriles undergo nucleophilic addition to the polar C=N bond in the same way that carbonyl compounds do. The most important reactions of nitriles are their hydrolysis to carboxylic acids, reduction to primary amines, and reaction with organometallic reagents to yield ketones. 

The reductive coupling of carbonyl compounds with formation of C-C double bonds was developed in the early seventies and is now known as McMurry reaction [38, 39]. The active metal in these reactions is titanium in a low-valent oxidation state. The reactive Ti species is usually generated from Ti(IV) or Ti(III) substrates by reduction with Zn, a Zn-Cu couple, or lithium aluminum hydride. A broad variety of dicarbonyl compounds can be cyclized by means of this reaction, unfunctionalized cycloalkenes can be synthesized from diketones, enolethers from ketone-ester substrates, enamines from ketone-amide substrates [40-42], Cycloalkanones can be synthesized from external keto esters (X = OR ) by subsequent hydrolysis of the primary formed enol ethers (Scheme 9). 

Preparation of secondary alcohols may be obtained from esters by associated use of RMgX and LiBH4 [25] or /-BU2AIH [26]. On the other hand, Af,N-disubstituted amides often react with only 1 mol of RMgX to give rather stable adducts that, on hydrolysis with aqueous acid, form carbonyl compounds [Eq. (15)] ... 

Enzymes are often used in kinetic resolutions, when one isomer reacts much faster than the other.25 This can be done on an industrial scale. Zeneca uses a dehalogenase on racemic 2-chloropropionic acid to obtain about 2000 ton/yr of the L-isomer for use in making a herbicide.26 Enzymatic resolutions may involve ring opening of epoxides,27 formation or hydrolysis of esters and amides, reduction of carbonyl compounds, and so on. Lipases are often used for this purpose.28 A typical example is reaction 10.16.29... 

A secondary amide is obtained by selective oxidation of a tertiary carbon center in adamantane with NaI04 in the presence of iron(III) perchlorate in acetonitrile (eq 18). Dimethylhydra-zones undergo periodate induced hydrolysis, at pH 7, to give carbonyl compounds in high yields (eq 19). However, these conditions are unsuitable for the hydrolysis of dimethylhydrazones derived from aromatic or a,unsaturated aldehydes because mixtures of aldehydes and nitriles are formed. 

The dialkylboranes and dialkylaluminums are also of value when partial reduction of an ester or amide is desired. The intermediates formed by the first hydride transfer are stable under the conditions of the reduction. Subsequent hydrolysis then provides the carbonyl compound at the aldehyde reduction stage. This method using diisobutylaluminum hydride has been particularly useful for reduction of esters to... 

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