Abstract: The invention relates to the field of organic synthesis, more specifically to a method for preparing novel organo-aluminum compounds. The compound in question can be used as a component in catalytic systems in processes for the oligomerization and polymerization of olefin, diene and acetylene hydrocarbons as well as in fine organic and organometallic synthesis. The essence of the method consists in reacting 3-methylene-exo-tricyclo[4.2.1.02,5]non-7-ene with triethylaluminium in the presence of the catalyst zirconocene dichloride in an inert gas atmosphere, preferably in argon or nitrogen, at room temperature, in an aliphatic or aromatic solvent for 5-7 h.