Synthesis of spiro[furo[3,4-b]pyran-4,3′-pyrroles] by reaction of pyrrolediones with malononitrile and tetronic acid

Substituted ethyl 2-amino-3-cyano-2′,5-dioxo-5′-phenyl-1′,2′,5,7-tetrahydrospiro[furo[3,4- b ]pyran-4,3′-pyrrole]-2′-carboxylates were synthesized by one-pot reaction of ethyl 2-phenyl-4,5-dioxo-4,5-dihydro-1 H -pyrrole-3-carboxylates with malononitrile and furan-2,4(3 H ,5 H )-dione.