Unexpected synthesis of 2,3,5,6-tetrahydro-1H-pyrrolo[3,4-c]pyridine-1,3,6-triones via double Michael addition/CS2 extrusion/double cyclization sequence.

Bis adducts derived from a double Micheal addition of the rhodanine to the azo-ene system of two molecules of 1,2-diaza-1,3-dienes (DDs) have furnished the corresponding 2,3,5,6-tetrahydro-1H-pyrrolo[3,4-c]pyridine-1,3,6-triones by means of CS2 extrusion/double cyclization sequence. The incorporation of two units (4 and 2 atoms) of DDs into fused bicyclic heterocycles represents a new application of this versatile class of molecules in heterocyclic synthesis.