DIMETHYLALUMINUM CHLORIDE CATALYZED ENE REACTIONS OF ALDEHYDES.

Article abstract of DOI:10.1021/ja00366a031

Dimethylaluminum chloride, which is a mild Lewis acid and a proton scavenger, catalyzes the ene reactions of aliphatic and aromatic aldehydes with alkenes containing a disubstituted vinylic carbon. Proton-initiated rearrangements do not occur, since the alcohol-Lewis acid complex formed in the ene reaction reacts rapidly to give methane and a nonacidic aluminum alkoxide. Formaldehyde and excess Me//2AlCl give good yields of ene adducts with all types of alkenes. With 1 equiv of Me//2AlCl, formaldehyde and mono- and 1,2-disubstituted alkenes give gamma -chloro alcohols resulting from cis addition of chlorine and hydroxymethyl groups to the double bond. This work is pertinent to the synthesis of alcohols.