Abstract
Novel penta- and tetra-cyclic cage-like compounds and dispiro heterocycles were obtained as a result of the microwave-assisted three-component domino reactions of heterocyclic or carbocyclic ketones, ninhydrin and sarcosine under solvent- and catalyst-free conditions. Interestingly, heterocyclic ketones afforded fused polycyclic cage-like compounds, whereas the carbocyclic ketones led to the formation of dispiro heterocycles.