The Reaction of Isobenzofulvenes with Heterodienophiles: A Simple Route to Indeno[a]heterocycles and 2-Heterosubstituted benzonorbornanes
Ronald N. Warrener,* Peter A. Harrison, Richard A. Russell
Centre for Molecular Architecture, Central Queensland University, Rockhampton,
Queensland, 4702, AUSTRALIA
The reaction of 6,6-dimethylisobenzofulvene with heterodienophile has been
investigated. In all cases, the Diels-Alder [4p+2p] adduct is formed
initially. The 2-oxabenzo norbornanes and 2-thiabenzonorbornanes are shown to
undergo rearrangement to indeno[a]heterocycles. Various indeno[a]furans and
indeno[a]thiophenes have been isolated and characterised by spectral means.
The 2-azabenzonorbornanes are more stable, thus allowing chemical modification
of the bicyclic ring.
Representative reaction products