Opiate dienes as dienophiles in the Diels-Alder reaction with 1-cyano-o-quinodimethane

The Diels-Alder reaction of opiate dienophiles with o-quinodimethanes is a route to tetrahydronaphthalene-fused opiates. This was gleaned from an examination of the Diels-Alder reactions of thebaine and a related opiate with the reactive diene, which led to the synthesis of tetrahydronaphthalene-fused opiates that are not easily available using other means. The 6-methoxy group of thebaine is also found to play a key role in the reaction.