Facile One-Pot Green Synthesis of Some New Annulated Polyfunctionalised 2-Amino-4H-Pyrans

Abstract

The reaction of cyclic CH-acids such as 5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclohexanedione, 4-hydroxy-6methyl-2H-pyran-2-one, or 4-hydroxycumarin with dialkyl acetylene dicarboxylates in the presence of tosylmethyl isocyanide (TosMIC) in polyethylene glycol (PEG-300) leads to new annulated highly functionalised 2-amino-4Hpyrans at room temperature in good yields.