The sialic acids waltz : novel stereoselective isomerization of the 1,7-lactones of N-acetylneuraminic acids into the corresponding γ-lactones and back to the free sialic acids

A novel internal rearrangement of the 1,7-lactone of N-acetylneuraminic acid into its γ-lactone in high yields is herein reported, together with the successive conversion into the parent free sialic acid. Overall these reactions further clarify the chemical behavior of Sias and their derivatives, which are increasingly becoming key players in many biological processes, including ischemic heart diseases