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A number of tricarbonyliron–lactone complexes have been prepared from vinyl oxirans by treatment with pentacarbonyliron. In certain cases two η3-allyl complexes were isolated from a single vinyl oxiran. Oxidation of the complexes by cerium(IV) ammonium nitrate in acetonitrile leads predominantly to β-lactones. The stereochemical integrity of the initial complexes is reflected in the formation of the oxidation products. Reduction of these products with lithium aluminium hydride gave the expected diols.

Several π-allyltricarbonyliron (lactone) complexes have been treated with an excess of benzylamine in the presence of Lewis acids to afford the corresponding lactam complexes by an SN2′-like process. These lactam complexes were oxidised in good yield with ceric ammonium nitrate to provide a novel route to a variety of β-lactam compounds. Simple chemical transformations of the resulting β-lactams have been investigated; these include the conversion of the vinyl and isopropenyl side chains into hydroxyethyl substituents and the reductive removal of benzyl groups to afford the parent NH β-lactams.

A number of tricarbonyliron lactam complexes were prepared from the corresponding lactone complexes by reaction with amines in the presence of ZnCl2 and on subsequent oxidation with CeIV gave β-lactams in excellent yield.

Tricarbonyliron lactones, on warming in tetrahydrofuran or benzene, afford products derived from decarbonylation, decarboxylation, and rearrangement pathways.

A number of tricarbonyliron lactam complexes were prepared from the corresponding lactone complexes by reaction with amines in the presence of ZnCl2 and on subsequent oxidation with CeIV gave β-lactams in excellent yield.

Tricarbonyliron lactones, on warming in tetrahydrofuran or benzene, afford products derived from decarbonylation, decarboxylation, and rearrangement pathways.

A variety of tricarbonyliron lactone complexes (1)–(12) undergo thermal decomposition upon warming in deoxygenated solvents to give products arising from decarbonylation, decarboxylation, and rearrangement pathways. The products of the reactions were characterised by spectroscopic or X-ray crystallographic methods, or in some cases, by independent synthesis. Mechanisms to account for the various transformations are also proposed.