A novel method for the synthesis of substituted and fused 3-cyano-4-methylmercapto-2(1H)-pyridones using α-oxoketen S,S-diacetals

α-Oxoketen S,S-diacetals (1), (4), and (6) react readily with cyanoacetamide in the presence of sodium isopropoxide in boiling propan-2-ol to give substituted and fused 3-cyano-4-methylmercapto-2(1H)-pyridones (2), (5), and (7) respectively.