Cleavage of 3-Aryl-5,6-dihydro-4H-1,2-oxazines Using Zinc and Aqueous Chelating Ethers: Efficient Methodology for N-O Bond Cleavage

A mild and efficient methodology for single pot ring opening of 3-aryl-4H-1,2-oxazines to γ-hydroxy ketones was developed using zinc and aqueous chelating ethers. The ether acts as ligand and co-solvent for the reaction. The ability of zinc ions to form stable complexes with chelating ethers activates the zinc towards reduction. Water is the proton source. Keywords: γ-hydroxy ketones, aqueous medium, ether, 1, 2-oxazine, Zinc, hydrogenation, amino, pyrrolidines, pyridines, 4-aminoalcohols