An Efficient Synthetic Strategy for Naphthalene Annellation of Norbornenylogous Systems

Abstract

Naphthalene annellation of norbornyl compounds can be readily achieved in good yields through in situ trapping of dibromonaphthoquinone (5), generated from 4 and sodium iodide, by the dienophilic norbornyl substrate. The dienophiles used include norbornadiene (which gave mono-adduct 8b or bis-adduct 3a depending on the conditions), norbornene, benzonorbornadiene (11), diene 9, and 13.