s Three-Component Synthesis of Spiro[Indoline-3,4'-Pyrano[3,2-b]Pyran]- 2,8'-Diones Using a One-Pot Reaction

A one-pot, three-component reaction of an isatin and kojic acid with an active methylene compound such as ethyl cyanoacetate, methyl cyanoacetate and malononitrile in methanol using catalytic amount of DABCO to give 2'- amino-6'-(hydroxymethyl)-8'H-spiro[indoline-3,4'-pyrano[3,2-b]pyran]-2,8'-diones in good to excellent yields under reflux conditions, is described.