Synthesis of penta- and tetra-cyclic cage-like compounds and dispiro heterocycles through microwave-assisted solvent-free multi-component domino reactions
Novel penta- and tetra-cyclic cage like compounds and dispiro heterocycles were obtained as a result of the microwave-assisted three-component dominoreactions 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