Synthesis of Functionalized γ-Spiroiminolactones through a One-Pot Three-Component Reaction of Isocyanides, Acetylenic Esters, and 6H-Indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one

A new and efficient isocyanide-based one-pot multi-component reaction has been described for the synthesis of novel ?-spiroiminolactone derivatives. Products were obtained by a three-component condensation reaction between isocyanides with acetylenic esters which was trapped with 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one (aromatic ketone) in CH2Cl2 without use of any catalyst or activator in excellent yields.