ChemInform Abstract: A Nickel Acycl as Propionic Acid Equivalent for Carbon‐Carbon Coupling Reactions. Application to the Synthesis of C25 Steroid Carboxylic Acids.

Succinic anhydride (I) reacts with nickel salts, e.g. (II), to form the nickel acyl (III) which is cleaved with methyl iodide (IV) to generate the intermediate nickel butyrate (V).