Preparation and properties of 9-methylenetricyclo[4.3.0.03,8]non-4-ene

A method for the synthesis of 9-methylenetricyclo[4.3.0.03,8]non-4-ene was developed by the reduction of 9-methylenetricyclo[4.3.0.03,8]non-4ene-2-ol and modifications on the tricyclo[3.3.0.03,7]octane skeleton. The formation of the target compound is characterized by the Diels-Alder reaction of methyl ketone with 7,9-dioxa-8-phenylbicyclo[4.3.0]nona-2,4-diene. The products exhibited variable pi splitting due to the interaction of their double bonds with their central six-membered ring.