Reaction between 3-hydroxy pyridine alkyl isocyanides and dialkyl acetylenedicarboxylate: synthesis of 4H-chromenes

Abstract

The reactive intermediate generated by the addition of tert-butyl and 1,1,3,3-tetramethyl butyl isocyanide and cyclohexyl isocyanide to dialkyl acetylenedicarboxylate was trapped by 3-hydroxy pyridine to produce highly functionalized 4H-chromenes in fairly good yields.