Acyl peroxides peroxycarboxylic acid

For the mechanism of azolide hydrolysis under specific conditions like, for example, in micelles,[24] in the presence of cycloamyloses,[25] or transition metals,[26] see the references noted and the literature cited therein. Thorough investigation of the hydrolysis of azolides is certainly important for studying the reactivity of those compounds in chemical and biochemical systems.[27] On the other hand, from the point of view of synthetic chemistry, interest is centred instead on die potential for chemical transformations e.g., alcoholysis to esters, aminolysis to amides or peptides, acylation of carboxylic acids to anhydrides and of peroxides to peroxycarboxylic acids, as well as certain C-acylations and a variety of other preparative applications. 

In this section we discuss the thermochemistry of some species with the general formulas, RC(=0)00H, RC(=0)00R and RC(=0)00C(=0)R. These species have the generic names peracids (peroxycarboxylic acids), peresters (percarboxylate esters) and acyl peroxides. The enthalpy of formation values are in Table 3. Three formal reactions that are discussed here are conceptually the same as in the earlier sections. Because now there is a carbonyl group present, we rewrite equations 5, 6 and 9 as equations 14, 15 and 16. 

Dialkyl peroxydicarbonates (17) are produced by reaction of alkyl chlo-roformates with sodium peroxide. OO-Acyl O-alkyl monoperoxycarbon-ates i 8 i are obtained from tine reaction of alky] chloroformates with perox-ycarbnxylic acids in the presence of a hase. Symmetrical di (organosulfonyl) peroxides (20, R = R2l) have been prepared by the reaction of organosul-fonyl chlorides with sodium peroxide or hydrogen peroxide in the presence of a base. Acyl organosullbnyl peroxides (19) are prepared from Ihe, organosulfonyl chlorides and a metal salt of a peroxycarboxylic acid. Acetyl cyclohexanesulfonyl peroxide has been produced commercially by the sulfoxidation of cyclohexane. QjH. in the presence of acetic anhydride. 

Peroxycarboxylic acid esters are utilized as initiators for radical polymerization and are interesting intermediates for the decarboxylation of carboxylic acids. They are generally prepared by the acylation of hydro peroxides with acid chlorides, acid anhydrides, or imidazolides in the presence of a base. Condensation of carboxylic acids (20) with /-butyl-hydroperoxide (21) has been smoothly achieved by the use of diethyl phophorocyanidate and NEt3 under mild conditions giving f-butyl peroxycarboxylates (22) in good yield.9... 

Peroxycarboxylic acids. Peracids are generally prepared by reaction of carboxylic acids with H2O2 in a strongly acidic medium (HaSOi, CHsSOjOH, 1,458). Lefort el al. now report that they can be made in a neutral medium by reaction of acyl chlorides with 857o H20i in THF, usually with added pyridine, which can markedly improve the yields in some instances. Diacyl peroxides are sometimes obtained as by-products. The peracids are obtained in 55-70% yield. ... 

Acyl carbamyl peroxides from peroxycarboxylic acids and isocyanates... 

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