An efficient synthesis of 6‐formyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid and some carbonyl derivatives of it and its 6‐acetyl homologue

Abstract

Abstract Starting with 1,1‐dimethoxy‐2‐propanone ( 1 ), 6‐formyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid ( 5a ) has been prepared in large quantities by a highly efficient, 4‐step synthesis. This compound, along with its one carbon homologue, 6‐acetyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid ( 5b ) has been reacted with several carbonyl derivative forming reagents to provide a series of side chains for β‐lactams. Among these carbonyl derivatives are styrylamides which were prepared from Wittig and Horner‐Emmons reagents. The preparation of the phosphonium salts and phosphonate esters is also described.