Reaction of crotonaldehyde with various ethyl aluminum chlorides in methylene chloride. A 1H‐NMR study

Abstract The reactions of crotonaldehyde (CA) with ethyl aluminum chlorides have been examined using a titration technique at low temperature. The titrations were followed by 1 H‐NMR spectroscopy. Evidence for complexes of the type (Et 2 AlCl) 2 CA and (Et 2 AlCl‐CA) 2 has been obtained. Ethyl aluminum sesquichloride undergoes sequential addition of CA to the EtAlCl 2 moiety, to the Et 2 AlCl moiety, and again to the EtAlCl 2 moiety. Ethyl aluminum dichloride undergoes ligand redistribution, alternately disproportionating and reproportionating, the ultimate product being EtAlCl 2 ‐CA 2 .