Reaction of Acylketene S,N-Acetals with Malonyl Chloride: Synthesis of Novel 1,5-Substituted 4-Hydroxy-6-methylthio-2(1H)-pyridones and 6,8-Substituted 4-Hydroxy-7-methylthio-2,5-dioxo-5,6-dihydro-2H-pyrano pyridines

Article abstract of DOI:10.1055/s-1988-27476

The acylketene S,N-acetals 1 react with one equivalent of malonyl chloride in the presence of triethylamine to give novel 1,5-substituted 4-hydroxy-6-methylthio-2(1H)-pyridones 3 in good yields.However, in the presence of excess of malonyl chloride (three