Cycloaromatization of enediyne model compounds via a reaction cascade triggered by hydrolysis of the α-alkynylmalonates

Diethyl α-methoxy-α-alkynylmalotate derivatives of cis -enediynes were synthesized and they produced toluenebiradicals via the reaction cascade triggered by ester hydrolysis. Deuterium labeling studies suggested that the reaction involved the self quenching process by fairly fast disproportionation of toluene biradicals producing zwitterionic species.