The electrochemistry of cephalosporin C derivatives: Part II. Cephalothin, sodium salt

Abstract The electrochemical behavior of cephalothin has been studied by a.c. and d.c. polarography, cyclic voltammetry, and coulometry in both aqueous and nonaqueous media in order to gain a greater understanding of the reaction pathways involved in cephalosporin reduction. The reductive allylic cleavage of the 3′-acetoxy function has been found to produce Δ 3 -deacetoxy and 3-exomethylene cephalothin compounds (geometric isomers) and stereochemical isomers of the 3′-exomethylene compound at the 4-position. The ratio of these compounds to one another is dependent on the experimental conditions used, with adsorption playing an important role. The reductive allylic cleavage of the S 1 −C 2 bond is a competitive reaction pathway. Δ 3 -Deacetoxy cephalothin may undergo further reduction, depending on the electrolysis potential selected.