The azaspiro[4.5]decane ring system is found in many natural products. This ring system can be envisioned as a dearomatized product obtained from the intramolecular nucleophilic addition reaction of the suitable arene substrate. Transition metal mediated synthetic protocols are well studied in this regard. We have found that arene-Ru complexes participate in tandem spirocyclization/ HWE olefination reactions in the presence of a suitable base and aldehyde. The dearomatized products were obtained from these spirocyclic complexes using effective oxidative demetalation protocols. The similar ring system was also constructed using hypervalent iodine reagents.