Functional derivatives hydrolysis

Macrocyclic complexes of zinc have inspired interest in varied areas such as supramolecular and biomimetic chemistry including hydrolysis enzymes, such as phosphatases and esterases, and also for the fluorescent detection of zinc. The polyaza macrocycles and their A--functionalized derivatives are particularly well represented. An important aspect of macrocycle synthesis is the use of metal templates to form the ligand. Examples of zinc as a template ion will be discussed where relevant. 

Enantiomerically pure 4,5,6-trihydroxy-norleucins (for instance 325) were obtained (197) from the hex-2-enono-1,4-lactone-2-mesylates (such as 152). These butenolides were stereoselectively hydrogenated to afford, upon treatment with sodium azide, the C-2-inverted derivatives, such as 324. Reduction of the azide function and hydrolysis of the acetal group gave the amino acids (namely 325), which were converted into lactones in acid media. 

Amides. Although similar to esters in terms of being a functional derivative of a carboxylic acid, amides, unlike esters, are relatively metabolically stable. In general, amides are stable to acid- and base-catalyzed hydrolysis. This stability is related to the overlapping electron clouds within the amide functionality and the corresponding multiple resonance forms. Amidases are enzymes that can catalyze the hydrolysis of amides. Nevertheless, amides are much more stable than esters. 

Like the amphoacetates and amphopropionates above, the amphohydroxypropylsulfonates are derived from hydrolyzed alkyl hydroxyethyl imidazolines. In this, amido-functional alkanolamine hydrolysis product is alkylated with sodium l-chloro-2-hydroxypropane sulfonic acid (see Figure 6.13). These products have good hard water tolerance and have applications including metal cleaning as well as personal cleansing. 

Alkaline hydrolysis of 5a appears to pass through l,244 leading to the same final product (o-carboxybenzenesulfonamide). The monomethyl and ethyl derivatives (9 R = Me, Et) hydrolyze slowly to 1 in dilute alkali,13 3-(o-carboxyanilino)benz[d]isothiazole-l, 1-dioxide (77) and functional derivatives form a tetracyclic system (78) on treatment with... 

The functional derivatives are all readily reconverted into the acid by simple hydrolysis, and are often converted one into another. 

Functional derivatives of carboxylic acids are recognized by their hydrolysis— under more or less vigorous conditions—to carboxylic acids. Just hkh kind of derivative it is is indicated by the other products of the hydrolysis. 

This method complements the widely used Prato and Bingel-Hirsch reactions. The derived, highly functionalized cyclopentenone and cyclopentenamine fullerene compounds are suitable for further functionalization upon hydrolysis and may serve well in the synthesis of new Cgo derivatives possessing uncommon and interesting properties... 

Acidity of Amides, Imides, and Sulfonamides Characteristic Reactions Reaction with Water Hydrolysis Reaction with Alcohols Reactions with Ammonia and Amines Reaction of Acid Chiorides with Salts of Carboxylic Acids Interconversion of Functional Derivatives Reactions with Organometallic Compounds 18.10 Reduction... 

The alkylation of 2-acetamido-5-nitrothiazole with bromoacetic acid or bromoacetamide in DMF, or with other alkyl halides, occurs predominantly on the hetero-ring nitrogen, furnishing iminothiazolines of type (40) and (41). In contrast, alkylation of the sodium salt of 2-formamido-5-nitrothiazole produces exclusively exocyclically N-alkylated products (42). Subsequent removal of the formyl group by hydrolysis or hydrazinolysis affords good yields of the aminothiazoles (43), which are convertible into functional derivatives by conventional procedures. ... 

Hammen equation A correlation between the structure and reactivity in the side chain derivatives of aromatic compounds. Its derivation follows from many comparisons between rate constants for various reactions and the equilibrium constants for other reactions, or other functions of molecules which can be measured (e g. the i.r. carbonyl group stretching frequency). For example the dissociation constants of a series of para substituted (O2N —, MeO —, Cl —, etc.) benzoic acids correlate with the rate constant k for the alkaline hydrolysis of para substituted benzyl chlorides. If log Kq is plotted against log k, the data fall on a straight line. Similar results are obtained for meta substituted derivatives but not for orthosubstituted derivatives. 

This chapter differs from preceding ones in that it deals with several related classes of compounds rather than just one Although the compounds may encompass sev eral functional group types they share the common feature of yielding carboxylic acids on hydrolysis and for this reason are called carboxylic acid derivatives... 

Hydrolyzed Vegetable Protein. To modify functional properties, vegetable proteins such as those derived from soybean and other oil seeds can be hydrolyzed by acids or enzymes to yield hydrolyzed vegetable proteins (HVP). Hydrolysis of peptide bonds by acids or proteolytic enzymes yields lower molecular weight products useful as food flavorings. However, the protein functionaHties of these hydrolysates may be reduced over those of untreated protein. 

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