Preparation of Ceph-3-em Esters Unaccompanied by ∆ 3 to ∆ 2 Isomerization of the Cephalosporin Derivatives. -Optimized conditions are found for the exclucive formation of ∆ 3 -cephem esters of type (III) from free acids (I) with alkyl chlorides (II). No ∆ 3 to ∆ 2 isomerizations occur by treatment of the acids with an equimolar mixture of cesium and potassium carbonate in 5:3 DMF/dioxane followed by addition of the chloride.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.