Polynuclear heterocyclic systems: Part VII. Addition of dimethyl azodiformate to 1‐arylcycloalkenes

Abstract

The reaction of dimethyl azodiformate with 1-phenylcyclopentene, 1 -phenylcyclohexene, I-(2-naphthyl)cyclopentene, I-(2-naphthyl)cyclohexene, 1-(6-rnethoxy-2-naphthy1)cyclopentene and 1-(6-methoxy-2-naphthyI)cyclohexene gives 2 : 1 (ester-olefin) adducts. The reaction mechanism of adduct formation is discussed.A convenient method of preparing six-membered heterocycles is via the Diels-Alder reaction 4 9 5 . One of the earliest examples of the Diels-Alder reaction is in fact the formation of heterocyclic system 1 by the addition of azodiformic ester to cyclopentadiene G .