Hydrolysis and alcoholysis

The mechanism of hydrolysis and alcoholysis has been described, and the greater reactivity of the 4-position over the 2-position is attributed to the greater stability of the transition complex (20) with respect to (21), hence its greater ease of formation. The hydrolysis... 

Lipases are generally inactive on the amide bond. One notable exception is the hydrolysis and alcoholysis of P-lactams by CAL-B [108-112]. For example, CAL-B... 

Although a number of factors affect structural evolution in sol-gel processing, many of the observed trends can be explained on the basis of the stability of the M-O-M bond in its synthesis environment. Structures which form in solution are the products of a successive series of hydrolysis, condensation and restructuring reactions. M-0-M bonds which are unstable with respect to hydrolysis and alcoholysis are absent. In borates this criterion precludes gelation for systems with insufficient fractions of 4-coordinated borons. In silicates... 

Figure 36 Complexes catalyzing hydrolytic cleavage of peptides, hydrolysis and alcoholysis of nitriles, decomposition of urea to carbon dioxide and ammonia, and alcoholysis of urea to ammonia and various...

C. K. Ingold and E. D. Hughes, "Dynamics and Mechanism of Aliphatic Substitutions," Nature 132 (1933) 933934 C. K. Ingold, E. D. Hughes, and S. Masterman, "Reaction Kinetics and the Walden Inversion. Pt. I. Homogeneous Hydrolysis and Alcoholysis of beta-n-Octyl Halides," JCS 140 (1937) 11961201 and subsequent articles. 

Several other alkylation reactions of benzyl chloromethyl ether have been reported using phosphorus compounds as nucleophiles. Hydrolysis and alcoholysis reactions of the reagent have been investigated along with the addition of the chloroether to propylene in the presence of zinc chloride. The alkylation of enamines with benzyl bromomethyl ether has been reported. ... 

The hydrolysis and alcoholysis reactions have been extended to the heterocyclic series. A systematic study has been published of the hydrolysis of unsaturated oxazolones derived from a selection of heterocyclic aldehydes. A detailed study of the synthesis and stereospecific hydrolysis and methanolysis of the (Z) and ( ) isomers of 2-methyl (or phenyl)-4-(thienylmethylene)-5(4F/)-oxazo-lones 435 and 437 has also been described (Scheme 7.144). The synthesis of 2-acylamino-3-(indol-3-yl or carbazol-3-yl)acryhc acid derivatives as potential antifertility agents via oxazolone hydrolysis has also been published. ... 

TABLE 7.39. A-ACYL DEHYDROAMINO ACIDS AND ESTERS FROM HYDROLYSIS AND ALCOHOLYSIS OF UNSATURATED 5(4H)-OXAZOLONES... 

Investigations into the mechanism of hydrolysis and alcoholysis of acyl halides have been largely concerned with acyl chlorides and in particular with benzoyl chloride and the related aromatic acid chlorides. This was a result of the relatively slow rate of hydrolysis of benzoyl chloride compared with acetyl chloride (although their alcoholysis rates are easily measurable) and it is only comparatively recently90 that stop-flow techniques have been used to measure the faster rate of hydrolysis. However, in spite of this limitation, considerable progress has been made towards elucidation of the mechanism or mechanisms of hydrolysis and alcoholysis of these halides. 

The effect of substitution in the benzene ring on reactivity of the acyl chloride group was investigated by a series of workers, using hydrolysis and alcoholysis. Data from these workers are compiled in Table 15 for mono-substituted benzoyl chlorides. 

RELATIVE RATE COEFFICIENTS FOR THE HYDROLYSIS AND ALCOHOLYSIS OF SUBSTITUTED BENZOYL... 

Benzo fused rings containing two or more electron-donating heteroatoms along with the boron atom, e.g. (57), are more stable to hydrolysis and alcoholysis than the corresponding open-chain derivatives, yet they are more or less sensitive to nucleophilic breakdown. For example, compound (77) is solvolyzed within five days in alcoholic solution at room... 

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