Abstract: The reaction of one-electron oxidation of alkanoic acids (I) and their amides (VI) on treatment with Na2S2O8-containing systems has been studied. As a result of the direct one-pot reaction acids (I) and amides (VI) are converted into γ- and δ-lactones, the reaction being regioselective and leading mainly to γ-lactones in up to 35% yield. The regioselectivity of the oxidative lactonisation depends greatly on the nature of alkyl substituents. The results obtained are presented in terms of a mechanism suggesting the generation of acyloxyl and amidyl radicals from (I) and (VI), respectively, followed by a rearrangement via a 1,5- or 1,6-H shift into the corresponding 3- and 4-carboxy- or -carboxamido-alkyl radicals. The latter undergo oxidative cyclisation to produce γ- and δ-lactones. The system Na2S2O8–NaCl–NaOH converts carboxamides (VI) into amines with loss of one carbon atom as a result of a Hoffmann type rearrangement.

Cite: Nikishin G.I. , Svitanko I.V. , Troyansky E.I.
Direct oxidation of alkanoic acids and their amides to γ-lactones by peroxydisulphate-containing systems
Journal of the Chemical Society, Perkin Transactions 2. 1983. P.595-601. DOI: 10.1039/P29830000595 OpenAlex

Dates:

Submitted:

Mar 1, 1983

Identifiers:

≡ OpenAlex:

W2141913911

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