Transition metal free intramolecular approach for the synthesis of cyclopenta[b]chromene derivatives from phenol substituted fulvene derived azabicyclic olefins

Abstract

A facile route towards the synthesis of cyclopentene fused chromene derivatives from strained phenol substituted fulvene derived bicyclic hydrazines is described. The reaction is proceeding through base catalyzed sequential intramolecular ring opening and ring closure of azabicyclic olefins. The transition metal free method provides an easy access to biologically relevant fused chromene ring system under relatively mild reaction conditions.