Indan-1,3-dione (1) reacted with 3-dicyanomethylidene-2-oxoindolines
(2a-c) in refluxed ethanol to afford 2-amino-3-cyanospiro{5H-indeno[1,2-b]
pyrane-4,3'-(1’-substitutedindoline)}-2’,5-diones (3a-c) which underwent
different reactions to afford new spiro{indeno[2',1':5,6] pyrano[2,3-d]pyrimidine-
5,3'-(1’-substitutedindoline)} (4a,b)-(12a,b) which are analogues of some
reported biologically active spiropolycyclic compounds.