A novel Dieckmann-type cyclization, the final step of the synthesis of a carbacephem derivative

Article abstract of DOI:10.1055/s-1991-26563

The treatment of the triacylamine, methyl 4-(dibenzoyl-aminocarbonylethyl)-2-oxoazetidine-1-acetate (2), with sodium bis(trimethylsilyl)amide leads to an unprecedented Dieckmann-type ring closure to form the anion of the carbacephem derivative, methyl 3-hydroxy-1-carbacephem-4-carboxylate, (3).